Potravinarstvo Slovak Journal of Food Sciences
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Total phenolic content and antioxidant activity of methanolic extract of selected wild leafy vegetables grown in Bangladesh: A cheapest source of antioxidants.
Get PDFNowadays, more attention has been paid on wild plants as new source of natural antioxidants. Therefore, methanolic extracts of 10 traditionally consumed wild leafy vegetables of Bangladesh were analyzed for their total phenolic content (TPC) and free radical scavenging activity. Folin-Ciocalteu method followed by spectrophotometric measurement was used to quantify the TPC of the selected wild leafy vegetables. Free radical scavenging activity was examined utilizing 1,1-diphenyl-2-picryl-hydrazyl (DPPH) assay. Different concentrations of the plant extract were applied to ascertain the dose response relationship in inhibiting DPPH free radical. The results revealed that the TPC ranged from 102.20 to 710.42 mg GAE/100g dry weight (DW). The highest TPC was observed in Bauhinia acuminata (Shetokanchan) while Leucas aspera (Shetodhron) exhibited the lowest TPC among the undertaken vegetables. The studied samples proportionately inhibited DPPH with increasing concentrations. At high concentration (500 µg.mL-1), the percentage inhibition of DPPH radical by plant extract ranged from 68.1 ±2.65 % to 93.1 ±1.23 %. The highest DPPH radical inhibition was observed in Bauhinia acuminata (Shetokanchan) (93.10 ±1.23 %), followed by Commelina benghalensis (Bat baittashak) (91.97 ±1.31 %), Hydrocotyle sibthorpiodes L. (Sakumubakla) (91.83 ±2.13 %). The lowest DPPH radical inhibition among the studied samples was observed in Leucas aspera (Shetodhron) (68.1 ±2.65 %). IC50 values measured by DPPH assay in this study ranged from 11.64 to 313.79 µg.mL-1. The study findings indicated that the samples under study possesses strong activity against DPPH, and thus could be used as natural antioxidants in the food and/or pharmaceutical industry
Food allergy and food intolerance knowledge of foodservice workers in Hungarian schools
Get PDFTo provide food for children with food allergy or food intolerances represents an increasingly important role in school catering services. The number of children with food intolerances is growing continuously; therefore, it is necessary to improve the knowledge of foodservice workers, who are responsible for food provision in school catering units in relation with food intolerances, food allergies. The main goal of our research is to assess and analyze the knowledge of food service workers and food handlers on food intolerances and to determine those factors, which may influence their knowledge. Our research was conducted by using paper and pencil questionnaires. The mean of test results was 89,16% while deviation was 12,26%. There were no correlations between the test results and respondents”™ education level, age group and the number of years working in food catering sector, and only partial correlation was detected with the job of the respondents. Based on the answers the food handling techniques of diet foods represented the poorest results. Our findings proved that the knowledge and food handling practice of food handlers regarding food intolerances and the preparation of diet meals should be improved
The concentrations of phthalic acid esters in a water bath at sous-vide heat treatment
Get PDFEsters of phthalic acid are common contaminants of the environment because of their large application in plastics. Phthalic acid esters are used as plasticizers in plastics, and they are also used in plastic intended for contact with food. In our research, we investigated the influence of heating on the migration of phthalic acid esters into the water used as a water bath. The water bath was used to heat the vacuum-wrapped meat, this heating is called the sous-vide method. The plastic thermostable bags containing phthalates were used on the meat packaging. Two esters of phthalic acid dibutyl phthalate (DBP) and di-2-ethylhexyl phthalate (DEHP) have been determined. Three packaged meat samples were heated in a water bath for one hour either at 50 °C or at 60 °C. The water was analyzed always before the heating and after the heating. Average DEHP concentrations in the water dropped after heating at 50 °C in two cases and average DBP concentrations rose in one case and declined in one case. Average DBP concentrations in water declined after heating at 60 °C, while average DEHP concentrations after heating at 60 °C in water increased. The concentrations of phthalic acid esters in the water ranged from 15.2311 μg.L-1 to 34.5645 μg.L-1 for DEHP and from 0.0433 μg.L-1 to 2.6529 μg.L-1 for DBP. The heating of vacuum-packed food in plastic phthalate bags in a water bath does not pose a great risk of contamination of water with phthalic acid esters
Investigating on the effect of freezing in different time periods on the chemical and qualitative changes of fish (Giant trevally)
Get PDFChanges in proximate composition of the Giant trevally were carried out for 0 days, 7 days, 14 days, 21 days, 28 days and 35 days at a freezing temperature. The moisture, ash, protein and fat contents were measured using standard methods. Based on obtained results, moisture content was decreased during different periods of freezing and its amount in fresh fish before freezing was (74.72%) that were decreased to 73.5%, 71.74%, 70.4%, 69.06% and 67.72%, respectively for 7, 14, 21, 28 and 35 days of freezing. The fat content in the fresh fish before freezing was (8.13%) that were decreased to 7.02% and 5.93%, and 5.33%, and 4.73%, and 4.13%, respectively, at 7, 14, 21, 28, and 35 days of freezing, respectively. The amount of protein in the fresh fish before freezing was (20.02%) that were decreased to 18.23% and 16.99%, and 15.75%, 14.51% and 13.27%, at 7, 14, 21, 28 and 35 days of freezing, respectively. Ash content in fresh fish before freezing was (1.21%) that decreased to 1%, 0.82% and 0.70%, and 0.58% and 0.46%, during 7, 14, 21, 28 and 35 days of freezing, respectively. it can be concluded that the best quality of frozen fish was obtained between 14 to 7 days of freezing
Evaluation of genetic diversity of edible honeysuckle monitored by RAPD in relation to bioactive substances
Get PDFThe aim of this study was clarifying the relation between genetic diversity of edible honeysuckle (Lonicera kamtschatica) and the major group of biologically active substances as total polyphenols content (TPC) including antioxidant activity (AO). Fruits of edible honeysuckle becomes more and more popular, especially in Europe. The current status of research on polyphenolic compounds in the berries of edible honeysuckle and their biological effects, including recommended utilization, are reviewed.The biological material including 14 cultivars of the edible honeysuckle (´Zoluška´, ´Amfora´, ´Pruhonický 44´, ´Vasilijevsky´, ´Moskovskaja´, ´Vojtek´, ´Sinoglaska´, ´Altaj´, ´Lipnická´, ´Kamčadalka´, ´Sinaja Ptica´, ´Fialka´, ´Modrý Triumf´, and ´Leningradský velikán´) originated from Czech republic (Žabcice near Brno). The content of TPC and AO were determined by location and its soil-climatic conditions and these environmental circumstances determines the RAPD profiles of analysed honeysuckle acessions, too. DPPH method was used to analyze AO and Folin-Ciocalteu method was used to determine TPC. The results of experiment showed that the highest value of AO was determined at the cultivars ´Zoluška´ (81.04 mg.L-1) and the lowest was measured in ´Kamčadalka´ (54.122 mg.L-1). On the contrary, the highest content of TPC was determined at the cultivar ´Kamčadalka´ (51.09 mg.L-1) and the lowest value was measured at the cultivar ´Pruhonický 44´ (21.65 mg.L-1). Phylogenetic trees were similar in genetic distance. The content of TPC and AO were not statistically significant in relation to cultivar. The analyzed cultivars of the edible honeysuckle were separated in 4 clusters according to used primers. In both gel images, the amplicon size ranged from 100 to 1,500 bp. We found that genetic diversity was partially related to content of total polyphenolic substances and antioxidant activity. Based on phylogenetic trees we have stated that variety ´Lipnická´, ´Sinoglaska´, ´Altaj´, ´Leningradský velikán´, ´Modrý Triumf´, ´Sinaja Ptica´ and ´Kamčadalka´ were grouped in the similar cluster. The highest genetic distance was determined at the variety ´Vasilijevskaja´ and ´Amfora´. In the same way, there were variety ´Vojtek´, ´Fialka´ and ´Zoluška´
Treatment of poultry slaughterhouse wastewater with combined system
Get PDFWith the interest to reuse and recycle the wastewater for technological use, this project aims to test the treatment of wastewater from poultry slaughterhouse industry from three main sections of the poultry slaughtering process, defeathering, eviscerating and cooling processes. The samples for the project were obtained from Izhevskoe a Kazakhstani company. The technology used is a combination of electrocoagulation, ultrafiltration, and photochemical system and its goal is to provide treated water that can be re-utilized in the poultry industry for sterilization of technical equipment without contaminating and affecting the quality of the poultry products. The treatment of wastewater samples lasted in total for 40 min. From the results, it was found that indicators such as BOD, COD, and phosphates had removal efficiency of almost 100%, while the microbiological colonies were all eradicated from then wastewater making the treated water microbes free. Hence, proving this system to be effective for the treatment of poultry slaughterhouse wastewater and safe for technological reutilization
The isolation and characterization of lipase from Carica papaya latex using zwitterion sodium lauroyl sarcosinate as agent
Get PDFMost of industrial lipases are derived from microbial sources, following by a wide variety of plants. Among plant lipases, lipase from Carica papaya latex has been the focus of intense and growing research due to low cost, easy acceptance by consumers and its unique characteristics. This enzyme has been successfully applied for lipid modification and synthesis of some organic compounds. However, research for its molecular structure has been limited due to the difficulty to isolate the enzyme from the latex matrix. In this study, we suggested a modified approach using sodium lauroyl sarcosinate to solubilize the latex, then the protein was precipitated by ammonium sulphate. We also carried out the characterization of the lipase obtained from Carica papaya latex. The results showed that freeze-drying the fresh latex could improve significantly lipase activity of latex powder in comparison with sun-drying or oven-drying. The zwitterion sodium lauroyl sarcosinate could solubilize nearly 50% of the latex and the achieved supernatant exhibited great lipase activity. There was no need to use an organic solvent to delipidate the latex prior to solubilization with sodium lauroyl sarcosinate due to possible denaturation of enzymes. The proteins which were fractionally precipitated with 50 - 60%, 60 - 70% and 70 - 80% ammonium sulphate saturation showed lipolytic activity. The fraction from 50 - 60% saturation with the greatest mass was subjected to ion exchange chromatography, SDS electrophoresis and kinetic parameter determination. The results showed the presence of two proteins with molecular mass ranging from 35 kDa to 55 kDa and both presented lipase activity. The Km and Vmax of the lipase fraction from 50 - 60% saturation was 1.12 mM and 1.2 x 10-6 mM.min-1.mL-1 respectively. So, the freeze-drying of papaya latex could help to preserve its lipase activity and the usage of sodium lauroyl sarcosinate could improve the isolation of the lipase from the papaya latex and pave the way for research on the molecular structure of Carica papaya latex lipases
The influence of cooking on the antioxidant properties and polyphenol content in buckwheat, barley and millet groats and the transfer of the compounds to the water
Get PDFThe research subject was the influence of the cooking process on the polyphenol content and antioxidant properties of groats (buckwheat groats, barley groats, millet groats) and on the colour parameters of the products. After groats cooking, also the water was tested for the polyphenol content and antioxidant properties that permeated into the decoction of the cooked raw material. The evaluation of the antioxidant properties of groats was conducted with the DPPH radical assay, the polyphenol content was determined with the Folin-Ciocalteu reagent, and the colour was determined with the trichromatic colorimetry method using the Konica Minolta CM-5 colorimeter (Osaka, Japan). The cooking process significantly lowered the content of polyphenolic compounds and antioxidant properties of the ready products. The best antioxidant properties after cooking were found in buckwheat groats and the weakest in millet groats. The polyphenol content in cooked products depended on the type of groats. Cooking significantly decreased the polyphenol content, but only in buckwheat and barley groats, as well as causing a change of groats colour as compared to uncooked samples. The most antioxidant properties were found in the water from cooking barley groats, and the least - from cooking millet groats. The most polyphenols permeated into the water from cooking buckwheat groats, and the least from cooking millet groats. All groats, except millet groats, darkened after cooking. In all types of groats, the correlation coefficients between colour parameter and general polyphenol content and the ability to scavenge DPPH radicals showed very strong negative dependences. The conducted research can help in designing the technological process of cooking buckwheat, barley and millet groats, and a way of using the water from cooked groats for consumption
Composition, quality characteristics and microstructure of the grain Triticum dicoccum
Get PDFThe compositional and quality characteristics of two wheat varieties Triticum dicoccum (Triticum dicoccum var. dicoccum, Triticum dicoccum var. rufum) produced in the Republic of Azerbaijan have been tested and are relatively useful in assessing their applicability to bread production. The wheat species studied, Triticum dicoccum, were found to have a higher protein and cell content, as well as essential proteins of lysine, phenylalanine, leucine and isoleucine, methionine and valine, relative to Gorbustan wheat varieties. The chromatographic method was used to determine the carbohydrate composition of the Triticum dicoccum grain. The following redistribution of low molecular weight carbohydrate fractions is noted: the maltose content is higher, and galactose, glucose and fructose are much lower than those of the modern wheat variety Gorbustan. Such a distribution of carbohydrates can reduce the formation of toxic products when baking bread. In addition, the wheat grain Triticum dicoccum is characterized by a higher content of sterols, in particular β-sitosterol. The antioxidant activity expressed as percentage inhibition of DPPG free radicals in the Triticum dicoccum grain is twice as high as this indicator for wheat of the commercial variety Gorbustan. By scanning electron microscopy, it has been established that the microstructure of the grain surface and the cross section has varietal characteristics. Grain Triticum dicoccum var. rufum has a thicker shell, tighter and tighter, unlike the grain of Triticum dicoccum var. dicoccum. With all the benefits of the wheat grain Triticum dicoccum, its technological properties were even worse. But the use of technological methods to boost gluten will ensure the production of high-quality healthy bread from old wheat grain
The correlation of intake phytate and tannin on serum transferrin receptor and hemoglobin in stunted overweight adolescents
Get PDFStunted overweight teenagers are at risk of having iron deficiency. Iron deficiency is caused by various factors including the high food absorption inhibitors of iron such as phytate and tannins. Phytate and tannin contain polyphenol compounds which have a strong ability to bind iron so that it inhibits iron absorption in the intestine. This study aims to analyze the correlation between phytate, tannin intake and serum transferrin receptor (sTfR) and hemoglobin in stunted overweight adolescents. The research method was a cross-sectional study of 64 stunted overweight adolescents selected by consecutive sampling in four high schools/vocational high schools in Banyumanik District, Semarang City. Phytate and tannin intake data using SQ-FFQ method. The serum transferrin receptor examination uses the ELISA method and the hemoglobin level uses the Cyanomethemoglobin method. The results of the study, most of the respondents had high phytate and tannin intake of 96.9% and 89.1%. Respondents with low serum transferrin receptor were 7.8% and low hemoglobin levels were 7.8%. There was no correlation between phytate intake with serum transferrin receptor or hemoglobin (p1 = 0.937 r1 = -0.010, p2 = 0.192 r2 = 0.165). Tannins were significantly correlated with serum transferrin receptor and hemoglobin (p1 = 0.005 r1 = 0.344, p2 = 0.002 r2 = -0.374). Based on multivariate analysis, tannin is a determinant of hemoglobin (R2 = 0.257). Conclusion is that tannin is positively correlated with serum transferrin receptor and hemoglobin in stunted overweight adolescents. Excessive tannin intake can cause deficiency in stunted overweight adolescents