1,721,044 research outputs found
A Variable Diffusivity Model for the Drying of Spherical Food Particulates
Full text linkThis is the author’s version of a work that was submitted/accepted for pub-lication in the following source: Walker, Lauren & Senadeera, Wijitha (2014) A variable diffusivity model for the drying of spherical food particulates. Applied Mechanics and Materials
Increasing manufacturing efficiency in the food industry
No full textMethods of incresing manufacturing efficiency is discussed and importance of scientific methods are described
Anaerobic digestion - an opportunity for energy
No full textAnaerobic digestion discussed in detail as an energy source
The Influence of Abrasive Pretreatment on Hot Air Drying of Grape
Full text linkThe drying of grapes is a more complex process compared to the dehydration of other agricultural
materials due to the necessity of a pretreatment operation prior to drying. Grape drying to produce
raisins is a very slow process, due to the peculiar structure of grape peel, that is covered by a
waxy layer. Its removal has been so far carried out by using several chemical pre-treatments.
However, they cause heterogeneity in the waxes removal and create microscopic cracks. In this
paper an abrasive pretreatment for enhancing the drying rate and preserving the grape samples is
proposed. Two cultivars of grape were investigated: Regina white grape and Red Globe red grape.
The drying kinetics of untreated and treated samples were studied using a convective oven at 50 ̊C.
Fruit quality parameters such as sugar and organic acid contents, shrinkage, texture, peel damage
(i.e. by SEM analysis) and rehydration capacity were studied to evaluate the effectiveness of abrasive
pretreatment on raisins. Abrasive pretreatment contributed to reduce drying time and rehydration
time. The treated and untreated dried grapes were significantly different (p < 0.05) in
sugar and in tartaric acid content. On the contrary, no significant differences (p < 0.05) in malic
and citric acids and in texture properties between untreated and treated samples were observe
Microstructural Approach Application for Morphological Change Determinations of Grapes during Drying
Full text linkGrape dehydration is practiced widely in the food industry with large yields of sultanas produced globally. This paper proposes an investigation into the microstructure changes of grapes as they are dried by imaging specimens at intervals during dehydration at two temperatures using scanning electron microscopy. Two main methods were developed to obtain the complex boundaries of cells present in grape tissue in over 36 SEM images. Segmentation of the binary image using an adapted watershed function obtained the most consistent and accurate morphological shape. This was compared to a secondary method which used Canny’s edge detection function, morphological closing and skeletonizing to outline the cellular microstructure. MATLAB was utilised to convert these boundaries into measurable areas so that quantitative data on average cell area, perimeter and cell axis lengths were acquired. It was found that over the drying time, the cell area and perimeter were reduced as expected. Some variability in the data was clear due to only single samples being analysed for each temperature and time combination. Trends in cell perimeter, diameter and shape will be used to demonstrate relationships between morphological structure, drying temperature, and duration. Detailed images of the microstructure were obtained, and a unique image processing algorithm was developed to quantitatively analyse the properties of this microstructure. The development of automatic image processing techniques and algorithms will enable quantitative data to be extracted from any image and extend to any plant/food material
Cycling helps rural economy in a sustainable way, some examples from the Third World
No full textEmission control is critical to slowdown global warming, reducing diseases in respiratory system and cardio-vascular systems. This is common for both developed and developing countries. It is proved that pedal powered operations generate no air pollution, no green house gases and little noise pollution. Also it is an efficient and environmentally sustainable energy form for transport and other operations and helps to reduce cholesterol, obesity, diabetics and depression.\ud
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Common method of pedal power usage is known as cycling, in sport, recreational and health activities. There are other cycling applications found in third world which helps to boost their economy specially in the rural sector. Improving the efficiency of non-motorized processing operations is vital for the rural economy.\ud
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In this paper, some applications of pedal power in processing operations are reviewed for the sustainability in the agro-food industry. Opportunities with other operations are also discussed
Fluidization behaviour of food materials: effect of moisture and shape
No full textChanges in fluidization behaviour of three geometrical shaped food particulates, cylindrica (beans), parallelipied (potato) and spherical (peas) with change in moisture content during drying were investigated using a fluidized bed dryer. Fluidization behaviour was characterised for cylindrical shape particles with three length\ud
: diameter ratio; 1:1, 2:1 and 3:1, parallepiped particles with three aspect ratios, 1:1, 2:1 and 3:1 and spherical particles
Economic development through solar drying technologies
No full textSolar drying of foods is described
Prediction of fluidization behaviour and a quasi-stationary approach to drying kinetics of irregular particulate food materials
No full textChanges in fluidization behaviour behaviour was characterised for parallelepiped particles with three aspect ratios, 1:1, 2:1 and 3:1 and spherical particles. All drying experiments were conducted at 500C and 15 % RH using a heat pump dehumidifier system. Fluidization experiments were undertaken for the bed heights of 100, 80, 60 and 40 mm and at 10 moisture content levels. Due to irregularities in shape minimum fluidisation velocity of parallelepiped particulates (potato) could not fitted to any empirical model. Also a generalized equation was used to predict minimum fluidization velocity. The modified quasi-stationary method (MQSM) has been proposed to describe drying kinetics of parallelepiped particulates at 30o C, 40o C and 50o C that dry mostly in the falling rate period in a batch type fluid bed dryer
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