Open Access Repository of Indian Theses

N, Sailaja



SYNOPSIS

Introduction
Post harvest technology is a multi disciplinary field requiring integration of a wide range of information and skills to develop a system for successful delivery of fresh produce to the end user.

	Extension of shelf life is the ultimate goal of post harvest research and this is achieved by retarding deteriorative process. Temperature, relative humidity and atmospheric composition are the environmental factors, which can be manipulated to lower the respiration rate and minimize the microbial spoilage if proper sanitation procedures are adopted. 

Tomato is the second largest vegetable crop of India, with an annual production of 5.5 million metric tones. India contributes to about 5.6 % of the world production.
Tomato is a climacteric fruit with a short shelf life under ambient storage conditions. When harvested at the mature green stage, it ripens within 8 days and shrivels thereafter resulting in loss of appearance and texture besides physiological loss in weight, cellular integrity, and in some cases even nutritional loss. Due to perishable nature of tomato fruits, it creates glut during production season and becomes scanty during off season.

Hence, there is a need to protect this perishable crop from post harvest losses so as to safeguard the grower’s investment and ensure ready availability of the crop to the consumers at affordable prices throughout the year. 

Processing of tomato into dehydrated products such as tomato powder can be considered as one of the other possible ways of tackling the problem posed by rapid ripening, senescence and spoilage of tomatoes in ambient conditions.

Presently some part of fresh tomato products are being processed and marketed in India in the form of traditional products like puree, paste, ketchup, sauce, pickles, chutney etc.  Further, these products continue to be processed by traditional methods involving energy intensive thermal processes, which generally degrade their quality. Also, because of their moisture contents, these products involve high packaging, handling, transportation and storage costs. 

The demand for dehydrated tomato is increasing rapidly both in domestic and in international markets with major portion of it being used for preparation of convenience foods. It has a potential to meet the increasing demand for quality products in India and abroad. Thus there is a need to develop suitable technology for processing and preservation of this valuable produce in a way that will not only check losses but also generate additional revenue for the country.

Objectives:
This research work emphasized on following main objectives:
1.	To optimize the post harvest treatments and storage conditions for tomato of 2 major commercial varieties for shelf life extension, minimize storage losses and improve quality using different treatments and storage conditions used such as Modified Atmosphere Packaging (MAP) and Controlled Atmosphere (CA) storage at low temperature and studies on physicochemical characteristics of tomato fruits during storage and ripening.
2.	Mathematical modeling for storage of tomato under modified atmosphere packaging
3.	To standardize optimum dehydration conditions and to develop improved pre treatments and process variables in different types of driers in order to obtain better dehydrated tomato product with higher storage stability, for 2 vars. of tomato i.e. Avinash and Madanapally.

Review of literature
A broad – based literature survey attempted on the subject of studies has resulted in compiling the status on the following related aspects:
	History, classification and anatomy of the fruits 
	Production of tomato
	Tomato composition and compositional changes during storage and ripening
	Extent of post harvest losses
	Storage of fresh fruits and vegetables using different techniques and treatments such as Modified Atmosphere Packaging (MAP), Controlled Atmosphere (CA) storage, skin coating etc., followed by particular discussion about  case of tomato in each section.
	Application of mathematical modeling for prediction of changes in shelf life and other physicochemical changes during storage of fruits and vegetables 
	Dehydration aspects of fruits and vegetables using different treatments and dehydration methods and quality changes during processing and storage with especial reference to tomato.

Material and methods
This part of the thesis includes details of various chemical, raw materials and instruments utilized in this study. Analytical methods and various techniques employed, particularly spectroscopic, chromatographic, color, texture and other physicochemical analysis along with statistical methods are described in this chapter. Some of the experimental methods particularly related to dehydration process are presented in the respective chapter.


Results and discussion
This chapter constitutes the major part of the thesis and presents all the results obtained in this investigation together with relevant discussion there on. The results are presented/ discussed in four sections.

Section 1: Studies on extension of shelf life of tomato using Modified Atmosphere Packaging.

Tomato fruits of two varieties of ‘Avinash’ and ‘Madanapally’ were harvested at mature green stage and stored at different conditions as follows:
	Modified Atmosphere packaging (LDPE films)
	Micro perforated bags (0.01% ventilated, PP films)
	Ventilated bags ( 1% ventilated, LDPE films)
	Wax coating (Waxol 9%)
Control samples, openly kept in same conditions.

	Storage studies were carried out at two different low temperatures i.e., 81C and 131C. Changes in physicochemical and visual appearance of the tomatoes such as color, texture, TSS, pH, acidity, sugars, chlorophyll, lycopene ripening index, cumulative spoilage, marketability and sensory quality of fruits were periodically analyzed during storage period.

 	Studies indicated that:
	Ripening and other associated changes in mature green tomato fruits were delayed and their shelf life was extended up to 42 and 35 days at 8C for varieties Avinash and Madanapally respectively by enclosing the fruits in MA packages made from LDPE of 25 micron thickness and appropriate permeability characteristics to CO2 and O2. 
	Stored fruits under MAP conditions at 8 1C and 13  1C were taken out and kept at ambient condition for ripening for 5 days. Ripened fruits showed very good overall sensory quality attributes for both the varieties of tomatoes.
	Using micro perforated poly propylene film packages for storage of tomato could extend the shelf life up to 35 and 28 days for var. Avinash and Madanapally respectively, but it was less effective in delaying the ripening process as compared to MAP.  
	The use of biodegradable skin coating with wax emulsion       (waxol 9%) was found to maintain the marketable quality of fresh tomato even after 28 days of storage at low temperature as against uncoated control fruits, which ripened and shriveled after 21 days. Visual attractiveness of the fruit was improved, ripening delayed and fruit firmness maintained.
	The two varieties of tomatoes showed significant variation in their shelf life in different treatments. Degradative process including chlorophyll breakdown, textural changes and color development (lycopene synthesis) were more prominent in Madanapally variety as compared to var. Avinash.

Hence there was a less extension of shelf life in case of var. Madanapally.

Section 2: Study on extension of shelf life of tomato using Controlled Atmosphere storage.

 In order to study the effect of Controlled Atmosphere (CA) storage on extension of shelf life and quality of mature green tomato of two major commercial varieties (Avinash and Madanapally) and also to optimize the storage conditions under controlled atmosphere storage, investigation were planned and carried out as follows:

Mature green tomatoes were handpicked, sorted, washed, treated with permitted fungicide solution (Benomyl, 500 ppm), surface dried and stored in CA condition at 10  1C and 90  5 % RH using different gas storage conditions of CA1=1% CO2 & 5% O2, CA2=2.5% CO2 & 5% O2 and CA3=5% CO2 & 5% O2 with N2 as balance gas.

    	Results confirmed the effects of Controlled Atmosphere (CA) storage on the post harvest physiology of mature green tomatoes by reducing the activity of tissue metabolism of fresh tomato.

	Chlorophyll breakdown was affected negatively by low O2 and high CO2 concentration and ripening was delayed in tomatoes stored under CA as compared to the control samples openly kept at the same temperature.
	Physiological loss in weight (PLW) and spoilage were reduced considerably and fruits preserved high marketability without a significant impairment of overall sensory quality after storage in CA and subsequent ripening at room condition.
	Combination of 2.5 % CO2 and 5% O2 was found to be the best gas composition for storage of both varieties of tomatoes. Increasing the CO2 level by 5% exhibited slight CO2 injury, which can adversely affect the fruit quality.
	Extension of shelf life was achieved by 8 weeks and 7 weeks for var. Avinash and Madanapally respectively, and stored fruits developed full red color during 5 days after removal from CA and ripening at room temperature.

Method developed in this study can be used for export of tomato in CA condition by ship to distant countries. 

Section 3: Mathematical modeling for storage of tomato under Modified Atmosphere Packaging.

Studies were planned and carried out to develop a mathematical model to predict the shelf life and changes in head space gas composition of tomatoes (vars. Avinash and Madanapally) stored in MAP at different storage conditions.

	Design Expert v.6 software was used to plan the experiments at different storage conditions and packaging materials.

	Data were collected by storage of freshly harvested mature green tomato in different polymeric packages with oxygen permeability of 3600 to 5200 cc/m2/day and CO2 permeability of 15000 to 27000 cc/m2/day at three different storage temperatures i.e., 8 1C, 13 1C and 211C. Changes in O2 and CO2 concentrations of head space of tomato packages and other parameters like color, texture, spoilage, physiological loss in weight and marketability were monitored periodically during storage to estimate the shelf life of tomatoes.

 Experimental data were subjected to statistical analysis to detect the significant models. Respective equations and mathematical models were obtained to predict the response i.e., shelf life and head space gas composition at different conditions.

	Mathematical models were tested to estimate the accuracy of the models by plotting graphs of the actual values versus the predicted response. Comparison of observed and predicted values for shelf life and gas composition in different conditions shows a reasonable close agreement between the experimental and predicted values.
	Models along with equations developed in this study can be adequately used to select the suitable packaging material and storage condition for desired shelf life without conduction repetitive experiments.



Section 4: Studies on the effects of different pretreatments and dehydration methods on dehydration characteristics of tomato. 

 In the next part of the research, experiments were focused on following aspects:
a) To study the effect of different pre drying treatments on physicochemical characteristics of tomatoes var. Avinash and Madanapally.
b) To determine the influence of different types of driers and dehydration conditions on physicochemical properties of tomato slices of two varieties.
c) To study the storage behavior of tomato powder regarding lycopene retention and browning reaction as affected by different packaging material, pre drying treatments and dehydration methods.

Dehydration process were carried out for tomato slices of two varieties after giving different pretreatments, such as CaCl2, KMS, CaCl2+KMS and NaCl along with control in different driers i.e., cabinet drier, solar drier and continuous conveyor drier (tunnel drier). Changes in quality characteristics of tomato slices as affected by dehydration process were studied for moisture content, sugar, titrable acidity, lycopene, dehydration ratio, rehydration ratio and non enzymatic browning. Storage studies were also carried out for a period of six months for tomato powder packed into different type of packaging material i.e., Metalized Polyester film (MP) and Low Density Poly Ethylene (LDPE) and changes in lycopene content and non enzymatic browning (NEB) were estimated during storage period.

	Results showed effectiveness of all four treatments on quality characteristics of dehydrated tomato as compared to the control samples.
	Potassium Metabisulphite (KMS) in combination with calcium chloride (CaCl​2) was found to have more protective effect on quality of dehydrated products during dehydration process.
	Among three different driers used in this study, tunnel drier samples attained best quality regarding to Lycopene retention, rehydration ratio, dehydration ratio and browning index.
	Storage studies showed highly effectiveness of treatments during storage. While control samples were totally dark brown with most degradation and loss of lycopene content, retarding effect of CaCl2 for browning and protective effect of KMS on lycopene was evidently observed in stored tomato powder. Combination of these two treatments presented highly acceptable tomato powder with red color and closer to the colour of fresh tomato powder even after 6 months of storage.
	ERH of tomato powder was found to be 33.8% with initial moisture content of 4.48%. Tomato powder remained free flowing up to moisture level of 6.48%, which is found to be critical moisture. Tomato powder is hygroscopic nature and hence, need moisture proof packaging material to protect them especially in higher RH conditions. LDPE films (75micron) and Metalized Polyester (25 micron) was found to be economical and provide moisture proof barrier.
	Metalized polyester (MP) was found to be a good packaging material to maintain the quality of tomato powder with respect to lycopene degradation and browning reactions.
	Tomato slices of var. Avinash could maintain better quality and exhibited better color retention and reconstitution characteristics as compared to the dehydrated samples obtained form Madanapally variety.

Pre treatment of 5 mm thickness of tomato slices (var. Avinash) with calcium chloride in combination with potassium metabisulphite using tunnel drier can be selected as best process condition, with subsequent storage of product in metalized polyester bags to protect the quality of tomato powder for longer period of time.

	The tomato powder can be reconstituted into juice or used as a starting material for preparation of products like sauce, ketchup, chutney, etc. It can be also used as flavouring agent/nutrient supplement in baby foods, health food, etc.

The main finding of the present investigation has been summarized in Summary and Conclusion.

A collective Bibliography for all the chapters is presented at the end of the thesis following Summary and Conclusion.





     Dr. K. V. R. Ramana				 Mehdi Ghiafeh Davoodi
        Research Guide 					 Candidate
 



PAGE  



1





English

TOXICOLOGICAL STUDIES OF SILVER NANOMATERIALS

P V, REKHA DEVI

BIOMONITORING OF THE GENOTOXICOLOGICAL IMPLICATIONS OF EXPOSURE TO BENZENE IN FUEL FILLING STATION ATTENDANTS

Maiti, Sabyasachi

Coastal change study along Midnapur Balasore coast of eastern India through integrated Remote Sensing and Geographic Information System based approach

Jakka, Naga Mahesh

SYNOPSIS OF THE THESIS

ISOLATION OF BIOACTIVE MOLECULES FROM THE ROOTS OF DECALEPIS HAMILTONII AND THEIR MODE OF ACTION


Free radicals are implicated in several degenerative diseases such as atherosclerosis, diabetes, arthritis, cancer and aging. Among the free radicals, the most damaging ones are the reactive oxygen species (ROS), superoxide, hydrogen peroxide and hydroxyl radical. The harmful effects of these free radicals can be prevented by antioxidant substances which scavenge the free radicals and detoxify them. There is epidemiological evidence that consumption of food rich in antioxidants play a vital role in prevention or slow down of the onset of cardiovascular diseases, cancer, neurodegenerative diseases and aging. Natural antioxidants have gained importance in recent years due to their safety to man and there is a great deal of interest in isolating natural antioxidant molecules from plant origin for their health implications.
Decalepis hamiltonii  (Wight & Arn) belongs to the family Asclepiadeceae. It grows largely in southern India in the hilly and forest areas of western ghats. Its aromatic roots are used in preparation of a juice known as “nannari”, which is believed to possess cooling effects and without any known toxic effects in humans. Earlier work has shown that the roots contain aldehyde, inositol, saponins, ketonic substances, sterols, amyrins and luoeols. Several flavor compounds have been characterized from the volatile extract of the roots of D.hamiltonii its essential oil is attributed mostly the presence of 2-hydroxy-4 methoxybenzaldehyde. Although the roots are believed to possess health promoting potential, they have not been scientifically investigated for specific beneficial effects nor the bioactive principles isolated. Therefore, the present study was undertaken to investigate the health promoting properties of the roots of D.hamiltonii.




TOXICOLOGICAL EFFECTS OF MERCURY ON BEHAVIORAL, MORPHOLOGICAL, BIOCHEMICAL,HISTOPATHOLOGICAL AND CYTOTOXIC PARAMETERS OF MOSQUITOFISH, GAMBUSIA AFFINIS

KHAN, PATAN USMAN

Developing Newer Termiticides from Natural Resources: Prospect of the future Management

Joseph, Elizabeth Abba

 1
 
SYNOPSIS 
Mitochondrial import of a subset of nuclear encoded tRNAs has been reported in a number of 
organisms including yeast, ciliates, higher plants and kinetoplastid protozoas. Assuming that 
mitochondria are genetic parasites and monophyletic in origin, it is difficult to explain the loss of 
a variable number of tRNA genes, apparently randomly, in different protists and higher plants. 
To sustain mitochondrial translation, Tetrahymena imports at least two third of their tRNAs 
while only tRNALys is imported in yeast. In higher plants import selectivity is again different even 
among closely related species. Thus, there appears to be a species-specific selectivity for 
tRNA import. 
 
The trypanosomatids, Leishmania andTrypanosoma, represent an extreme situation, where all 
the tRNAs are imported. However, there is an isoacceptor specificity; for example in 
Leishmania, while tRNAGln(UUG) is imported, tRNAGln(CUG) is not imported. Studies on the 
mechanism of these processes in vitro and in organello are scarce. 
 
To study this import process in detail, an in organello import assay system was developed, and 
the distribution of the imported tRNA in different mitochondrial compartments was studied. 
The main aims of this study were:- 
 
1.  To study the bioenergetics of RNA import through the double membrane of L ishmania 
mitochondria. The proton motive force generated during electron transport provides energy 
for several mitochondrial transport systems. Experiments were carried out to study the role 
of this proton motive force in tRNA import. 
2.  To study the importance of D arm of tRNATyr for its mitochondrial import in vivo and in 
vitro.  Site-specific mutagenesis of the D arm sequence has carried out and its effect on 
both outer and inner mitochondrial membrane transfer was examined.  
3.  To identify and characterize import signals present on other importable tRNAs. A 
combinatorial RNA library of random sequence was used for Systematic Evolution of 
Ligand by EXponential enrichment (SELEX) using Leishmania mitochondria. The 
interactions among the evolved ligands were also studied. 
 
It was observed that tRNA import process was dependent on ATP hydrolysis. Non-
hydrolysable ATP analogues had no stimulatory effect on tRNA import in vit o.The 
energetics of this process was also studied in vitro using different inhibitors and uncouplers 
of membrane potential. It was predicted that F1F0 ATPase of inner mitochondrial membrane 
probably uses ATP to generate protonmotive force across the inner membrane, which  
 
 2
Synopsis 
 
 
 
actually drives tRNA import. In support of this hypothesis it was found, that oligomycin, an 
inhibitor of F1 0 ATPase, could inhibit the inner membrane transfer of tRNA. Involvement of 
both the electrical and chemical components of protonmotive force was proved in 
experiments using valinomycin/K+ and nigericin (un-couplers of DYand DpH component of 
protonmotive force, respectively). In both cases, the efficiency of inner membrane transfer 
was lowered significantly. From these observations and kinetic experiments, a stepwise 
transfer model of tRNA import was proposed for Leishmania mitochondria. 
 
With different D arm mutants, it was shown that the signal sequence requirements, both in 
terms of primary sequence and secondary structure were different for the outer and inner 
membrane of Leishmania mitochondria. At the outer membrane, a conserved primary signal 
sequence was required, whereas for inner membrane transfer, the stem loop structure apart 
from the primary sequence was essential. 
 
“SELEX” or Systematic Evolution of Ligand by EXponential enrichment approach identified a 
number of putative import signals. Based on homology analysis, a number of import signals in 
different parts of physiological tRNAs was identified and experimentally verified. When used in 
combinations, the evol ed ligands show both positive and negative cooperativity in terms of 
binding and import. These novel antagonistic and cooperative interactions might constitute the 
actual mode of regulation of physiological tRNA import in Leishmania mitochondria. 
 
Further, an autonomous tRNA import complex from the inner membrane of Leishmania 
mitochondria was purified and characterized. This complex, (RIC), was purified from the crude 
DOC extract of inner membrane of Leishmania mitochondria by a RNA affinity chromatography. 
This receptor inner membrane complex or RIC was used for functional reconstitution of RNA 
import system in proteoliposomes. Further, in complementation assays it was observed that 
tRNAs could be imported into the human mitoplasts, in presence of RIC.  Both protein profile 
and morphology of this complex was also determined.  
 
 
 
 
 
 
 
 


Fine Particulate Characterization and Source Apportionment

Y, Mahalaxmi

 
 
6 
 
ABSTRACT 
  
The actinomycete Amycolatopsis sp. RSP-3 is used for the production of rifamycin B by 
fermentation. Various fermentation strategies such as submerged fermentation, solid state 
fermentation and whole cell immobilization were exploited to maximize the production 
of rifamycin B by the selected actinomycete.  A two step methodology was employed for 
optimization of rifamycin B. In the first stage, the conventional one variable at a time 
methodology was employed to select the suitable fermentation parameters. In the second 
stage, taguchi methodology was employed to fine tune the levels of the critical 
parameters those noticed to influence the production of rifamycin B drastically during 
optimization studies carried out via conventional one variable at a time methodology   
The production of rifamycin B under submerged fermentation was maximized by 
optimizing the physical process parameters such as pH, temperature, speed of agitation, 
medium volume, incubation time, age and size of inoculum level, concentration of 
calcium carbonate and nutritional parameters such as carbon and nitrogen sources and 
investigated the effect of barbital a very well known inducer of rifamycin B. Under 
submerged fermentation, 4.5 g/L of rifamycin B production was observed when 
fermentation was carried out with 25 ml medium volume, containing glucose as carbon 
source and soya bean meal and potassium nitrate as organic and inorganic nitrogen 
sources adjusted to pH 8.0 when inoculated with 72 hours grown 10% inoculum and 
incubated at 28 
o
C at an agitation speed of 250 rpm, for a period of 9 days. Addition of 
barbital after 24 hours of inoculation elicited a 10% improvement in rifamycin B 
 
 
7 
 
production. During optimization studies it was observed that the optimum concentration 
of barbital depends on the concentration of inorganic nitrogen source selected.  
Further enhancement of rifamycin B under submerged fermentation was carried out using 
taguchi methodology with L18 orthogonal array. Six critical fermentation controlling 
factors such as inoculum level, soyabean meal, glucose, calcium carbonate, barbital 
concentrations were selected for this study. The design of experimental methodology by 
taguchi approach aided in identification of most significant parameters that effected 
rifamycin B production at interactive and individual levels. The data suggested that 
production of rifamycin B was mostly influenced by the variation in concentration of 
soyabean meal. It is interesting to note that under both methodologies (conventional i.e., 
one variable at a time as well as Taguchi) this nutrient  was observed to be significant for 
production of rifamycin B. Approximately a 13.19% improvement was observed in 
rifamycin B yields on optimizing significant parameters using this methodology. 
Whole cell immobilization of Amycolatopsis sp. RSP-3 was attempted using various 
supports such as alginate, agar and coconut fiber. Of all the supports that were, screened 
coconut fiber was found to be suitable support for the whole cell immobilization of 
Amycolatopsis sp. RSP-3. Comparative evaluation of different supports, suggested that 
growth of the microorganism should not be restricted and free diffusion of gases and 
nutrients should be facilitated. Repeated batch production of rifamycin B suggested that 
yield (4.5±0.1g/L) was observed to be consistent up to 5 cycles and then decreased 
further. Though the production of rifamycin B was observed to be consistent upto 5 
cycles, a 10% decrease in production was observed when compared to free cells. 
 
 
8 
 
Under immobilized conditions process parameters such as substrate weight, medium 
volume, level of aeration, size of inoculum, number of cycles, concentrations of glucose 
and soyabean meal were investigated. Four grams of coconut fiber was found to support 
rifamycin production. All other factors remained the same as that for free cells. 
The production of rifamycin B under solid state fermentation conditions was investigated. 
Various agricultural wastes which act as a source of carbon were selected for screening. 
Rice bran, corn husk, wheat bran, and corn cobs were screened.  Among all these 
agriwastes, corn husk supported more rifamycin B production by selected 
microorganism. Hence it was selected as the solid substrate and further studies were 
carried out to maximize the rifamycin B production under solid state fermentation. 
The process parameters such as initial pH, moisture level, particle size, age and size of 
inoculum, length of incubation time, effect of barbital, glucose, soyabean meal, 
potassium nitrate were optimized under solid state fermentation conditions.  Here too 
taguchi methodology was employed to optimize the maximum requirements of critical 
factors such as inoculum level, length of incubation time, concentration of nutritional 
factors such as soyabean meal, potassium nitrate, glucose and barbital. An L-18 
orthogonal array with the above mentioned parameters as controlling factors was used for 
fine tuning the antibiotic production. The data revealed an overall yield of 18.75 g/Kgds 
of rifamycin B which accounted for nearly 100% improvement in rifamycin B 
production. 
Extraction of rifamycin B from solid substrate was carried out using phosphate buffer at 
pH -7.3, under agitation at 200 rpm and temperature of 28 
o
C for 4 hours. 
 
 
9 
 
This is the first report on production of rifamycin B using corn husks and coconut fiber 
discs as solid substrate and immobilization support respectively. The investigations 
suggest that  production of rifamycin B by solid state fermentation is more beneficial 
compared to other fermentation strategies(submerged(5.12 g/L) and whole cell 
immobilization(4.5±0.1 g/L)) as it supported high titers of rifamycin B production(18.75 
g/Kgds). 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 


STUDIES ON PRODUCTION OF RIFAMYCIN BY AMYCOLATOPSIS SP. RSP-3

V, SRIDHAR

CHAPTER 6 Summary and Conclusion ________________________________________________________________​​​​​​​_____________


Traditional foods have occupied an unique place in the dietary practices of population in different countries (Kulkarni, 1989) and are known for their unique texture and taste. The art of preparing traditional foods has been evolved over thousands of years with each region in the world having its own characteristic products. These foods are prepared in every part of the world based on the traditional knowledge enriched through many generations. 
In traditional foods, snack foods hold a significant share. Webster’s New Ninth Collegiate Dictionary (1985) defines the noun ‘snack’ (First recorded use, 1757) as ‘a light meal, foods eaten between regular meals, food suitable for snacking’ and the verb snack as ‘to eat a snack’. Kulkarni (1989) stated that snacks, which are mostly based on the locally available raw materials, originated probably from a need to overcome the monotony in the diet. 
In India, Ministry of Food Processing, India (MFPI) estimates that the size of the food processing Industry is Rs.3150bn (US$70bn), including Rs.990bn (US$22bn) of value added products and it is expected to grow at the rate of 9-12% annually on the basis of an estimated GDP growth rate of 6-8% during the tenth plan period. Estimated Indian snack food market is over 400000 tons in terms of volume and Rs.100bn in terms of value and has grown at over 10% per year during the period 2000-2003.  
Among the innumerable traditional foods of India, snack food items are very popular, especially those based on fried legume. Legumes and pulses play an important role in the Indian diet for they supplement not only the quantity and also quality of protein by balancing essential amino acid pattern in the predominantly cereal based diet of bulk of Indians. They are good sources of lysine rich protein. The world total pulse production in the year 2003 (FAO, 2004) was 55520000 MT and India’s production was 11933000 MT which contributes nearly 21% of the world’s production.

The chickpea cultivars Desi (A1) and Kabuli (L 550) vary significantly in their physical properties like seed  color, size 100 seed weight, 100 seed volume. The color related parameters such `L’, `a’ and `b’ showed significant differences between the cultivars indicating kabuli variety having lighter color compared to desi. The volume and weight of 100 seeds was also higher for kabuli variety while its true density was lower.  

Broad objective
The proposed investigation will focus on the process of boondi preparation, and to understand the role of raw material, additives and processing parameters on the product characteristics including rheological and sensory characteristics. 
Specific Objectives
	To investigate the effect of popular Kabuli and Desi chickpea varieties available in India and examining their suitability for boondi making.
	Detailed rheological characterisation of the chickpea flour suspensions and sensory quality of the product.
	To study the effect of additives on rheology of chickpea suspensions and standardisation of process parameters of boondi.
	Finding the relationship among rheological, textural and sensory properties.
Plan of Work
	Suitability of Kabuli (Variety - L550) and Desi (Variety - A1) types of chickpea for the preparation of boondi. 
	Assessing the quality characteristics of commercially available boondi with an emphasis on texture and sensory attributes. 
	Rheological studies of  Kabuli’ and Desi type chickpea flour suspensions
	Effect of additives, such as, refined groundnut oil, sodium chloride (NaCl), sodium salt of Carboxy methyl cellulose (Na CMC), and guar gum on the rheology of chickpea suspensions and quality characteristics of  prepared boondi based on instrumental and sensory analysis.
	Standardisation of the process parameters of boondi making using an integrated approach of relating rheological characteristics, process parameters and product quality.


Chapter 1 covers the introduction regarding legume based products in general and also fried snacks from pulses and in combination with cereals. Available information on Chickpea has been classified under cultivars yield, composition, of major and minor constituents and the effect of commonly used processing steps on these constituents. However, published literature covers very little information regarding the detailed sensory and instrumental characteristics of chickpea based products and the necessity for undertaking boondi a fried product from chickpea as a case study for a systematic investigation gets justified. 
Chapter 2 mainly describes the physico-chemical properties of the Chickpea cultivars i.e Desi and Kabuli. 
	The chickpea cultivars Desi (A1) and Kabuli (L 550) vary significantly in their physical properties like seed  color, size, 100 seed weight and 100 seed volume.  

	The color related parameters such `L’, `a’ and `b’ showed significant differences between the cultivars indicating kabuli variety having lighter color compared to desi. The volume and weight of 100 seeds was also higher for kabuli variety while its true density was lower. 

	Between the dry and wet milling, higher yield of dhal was obtained from wet milling, which was found to be true in both the cultivars. An extra yield of 2 to 4% was obtained in wet milling. Between the cultivars, Desi was found to be the higher dhal yielding cultivar in both dry and wet milling methods. 
	SEM microphotographs of Kabuli chickpea were found to be similar to that of Desi variety, but the split dhal surface showed some difference in the pattern.
	After grinding the flour obtained was sieved and the particle size distribution showed indicating that 100 to 120mesh particle size forms the major bulk of flour. However, marginal differences in yield of different fractions were observed between the two varieties. 
	Fat, ash and protein contents were more in kabuli than desi and fibre content was more in desi than Kabuli.
	Electronic nose analysis of chickpea flour, indicated the possibility of differentiating the variations in odor associated with varietal difference and also dhal obtained from dry or wet milling of the gram.  Grinding of dhal at low speed could be easily separated as the difference in odor was relatively larger. 
	The gel electrophoresis pattern of chickpea showed that as about fifteen protein bands in flours from both the cultivars, either in phosphate or SDS buffer containing ß-mercapto-ethanol. There were some differences observed in the band thickness but the pattern was very similar.
	The Rapid Visco Aanalyzer profile did not show significant difference between the two cultivars

Chapter 3 deals with the rheological properties of Chickpea flour dispersions. and modeling. The rheological studies were conducted for time independent as well as time dependent properties of chickpea flour dispersions. 
	Time independent rheology of chickpea flour dispersions were measured as a function of shear rate, up to 500s-1. Apparent viscosity and shear stress were measured. The shear rate / stress and apparent viscosity data were analyzed by fitting with well known rheological models namely., Herschel-Bulkley and Cross equations.
	Chickpea flour dispersions behave like a pseudoplastic or shear-thinning fluid. The pseudoplastic behavior indicates the continuous breakage or re-organisation of structures, resulting in a decrease of resistance when applying force. The pseudoplastic behavior is due to the presence of a) compounds with high molecular weight or particles at low concentrations b) high interaction among particles, causing their aggregation or association by secondary bonds c) large axial relation and asymmetry of the particles, requiring their orientation along the stream lines d) variation of shape and size of the particles, allowing them to pile up. and e)  Non-rigid or flexible particles that can suffer a change in their geometry or shape. 
	The apparent viscosities measured at a shear rate of 100s-1, increased from 213 to 1497.3 mPa s. when the concentration of solids in the dispersion increased from 34 to 44% in desi flour.
	The Cross model constants were significantly affected by the influence of solids concentration in the dispersion. The zero shear viscosity increased from 437.10 to 4218.87 Pas when the solids concentration increased from 34 to 44%. The relaxation parameter () also increased from 0.0102 to 0.0179s along with ‘m’ which also increased from 0.1213 to 0.2586. The increase in ‘m’ values indicated that the flow behaviour decreased with the increasing concentration of solids in the dispersion. The same was also reflected in the power law constant ‘n’ which is known as the flow behaviour index. 
	As fine particles have more surface area, leaching out of soluble and / or colloidal particles to dispersion is higher which leads to higher  values for smaller particles (<100 microns).
	Among the additives used in the present study, salt and oil reduced the viscosity of the chickpea flour dispersions while CMC exhibited a reverse trend. 
	Guar gum, gum Arabic and pre gelatinized rice and corn starches were added to  chickpea flour dispersions at various levels. Gums increased the viscosity at much lower levels compared to modified starches. 
	Chickpea flour dispersions exhibited time-dependent characteristics that were affected by the temperature of measurement and the shear-rate employed. The models of Peleg, Weltmann and Hahn-Ree-Eyring were suitable to characterize the time-dependent rheological behavior of chickpea flour dispersions while the model of Peleg was marginally better as evidenced by the lowest root mean square (RMS) error values of 0.77 to 5.17%. The coefficients obtained from these models indicated that higher breakdown occurred at low temperature as well as at high shear-rates. 
Chapter 4 deals with bench mark studies from market samples of boondi along with laboratory samples including both instrumental and  sensory characterization.  
	PCA analysis was carried out to position these samples which indicated that the market samples segregated with respect to oily and fried gram aroma, firmness and crumbly notes. The color showed greater difference as surface was coated with different levels of chilli powder. They did not show significant difference in other attributes. 
	Uniformity of boondi, porosity, firmness and crumbly notes were comparable, fried gram aroma of samples A and B were good, but both oily appearance and mouth feel showed greater differences. Samples A, B, and C differed from D, E and F as the latter had lower oily appearance and oily mouth-feel. They also differed in their firmness values as indicated by the sensory data.
	Boondi samples prepared with 40 and 42% solids concentration in the dispersion were located nearer to desirable sensory attributes like uniformity in size and fried gram aroma.
	Simultaneous optimization was performed on selected important quality characteristics of boondi like oil content, crumbliness, uniformity of boondi and overall quality, by imposing desirability constraints 
	Based on the trails, a maximum desirability score of 0.7074 colud be achieved when the solids concentration in the dispersion, temperature and time were 40.4%, 182°C and 240s, respectively. The predicted corresponding responses were oil content, uniformity of boondi, crumbliness and OQ and their values were 56.34%, 12.82, 8.09 and 12.65 respectively. 
	Confirmation of the results were done by making the product boondi with optimized levels and subjected to sensory evaluation by a trained panel. The results indicated that no significant (p<0.05) difference between predicted and experimental values for different attributes, validating the results from optimization studies. 
	Correlations of results from rheological measurements and sensory profiling by partial least squares analysis  (PLS) indicated that two Cross model constants such as η0 and flow behavior parameter `m’ were closely associated with uniformity and OQ of boondi.
	Textural characteristics of boondi were determined by subjecting to compressive strain at different crosshead speeds from 0.01 to 10 mms-1. The principal component analysis (PCA) was found to be a very useful tool in segregating textural parameters associated with crosshead speeds in boondi. The fracture strain, maximum force and number of peaks were positively related while slope was negatively correlated with crosshead speed. 
	Boondi samples made from flour with smaller particle size were harder, less crumbly and crisp. However, boondi from flours with bigger particle size were more crumbly, and porous but more oily. Grinding the dhal to suitable particle size distribution is essential to get boondi with desirable quality attributes. 
	High amount of salt (3%) in chickpea flour dispersions resulted in more firm boondi loosing its characteristic crumbly attribute. Samples lower salt level (1-2%)  did not adversely affect the boondi quality.
	The desirable golden brown color of boondi was closely associated with samples with low levels of salt (1-2%) and oil (2.5 to 5%).
	There was a reduction in the oil content of boondi as it came down from 55.84% to 51.51% when 0.5% of CMC was added, but higher amounts did not result in any beneficial effect. 
	There was a marginal reduction in the oil content of boondi, when the gum Arabic level was added at 5.00% level.
	The beneficial effect of guar gum in terms of  reduction oil content was not reflected in the texture of boondi as the crispness was lost in the product
	Addition of pre gelatinised rice flour improved crispness and resulted in more porous nature of the fried product. Addition of pre gelatinized corn starch at 2.5% resulted in product with lowered oil content. It was less firm compared to control. Addition at 5.0% also showed the similar pattern.
Chapter 5 covers the effect of processing on the functional properties of chickpea. The SDS-PAGE electrophoretic pattern from phosphate buffer extracts of chickpea flour indicated the absence of high molecular weight protein bands in the steamed dhal or steamed flour. 
	The treated flour samples were used to prepare the fried snack boondi. Evaluation of boondi showed that use of steamed flour or the flour from steamed dhal resulted in loss of spherical shape of the product boondi. 
	It was observed that thermal treatment leading to absence of protein band might be due to reduced solubility of protein as indicated by SDS PAGE electrophoresis. 
	Thermal treatment of chick pea dhal / flour causes denaturation of this protein fraction, and leads to `loss of solubility’. The flour from thermally treated chickpea flour may be unable to impart spherical shape to boondi. Sphericity is a desirable characteristic of boondi.
	The results indicated that some fraction of phosphate buffer soluble protein may be responsible for imparting sphericity to the boondi. Though it is not a common practice to process chickpea for product preparation some amount of heat generated during large scale grinding of chickpea.
	Protein extracted from these treated flours, was subjected to gel-filtration chromatography followed by SDS-PAGE and the results indicated that the high molecular weight protein fraction content decreased significantly in heat treated samples compared to control. 
	The studies on sensory quality of boondi indicated that the chickpea proteins play a vital role in governing the product texture and quality, which is evident from the changes brought about by absence of high molecular weight protein bands after different thermal treatments as reflected in SDS PAGE electrophoretic pattern and gel filtration chromatography profile.
	It is important to note that, care should be exercised during large scale milling of chickpea to avoid excess heat effect on the flour, so that desirable quality characteristics of fried product could be achieved.











































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