[en] Whey powder was sterilized by gamma waves application. As a source of irridiation isotope 60Co was used in Institute of Nuclear sciences ^Boris Kidrich^, Vincha-Belgrade (Yugoslavia). The applied doses were: a, b, c, d, and e Kgy. The dose d was radappertization. After whey powder irradiation no adverse changes of organoleptic properties were noticed

[en] In this study, H₂ was produced in a two-stage biological process: I) first stage; the dark fermentation of cheese whey wastewater, which is rich in lactose, by mixed anaerobic culture grown at thermophilic temperature in a continuously running fermentor and ii) second stage; the photo-fermentation of the residual medium by R. palustris strain (DSM 127) at 31^oC under illumination of 150 W in batch mode, respectively. In the first part of the study, the effluent from the dark fermentation reactor was used either as it is (no dilution) or after dilution with distilled water at varying ratios such as 1/2 , 1/5, 1/10 (1 volume effluent/5 volume distilled water) before used in photo-fermentation experiments. In the second part of the study, L-malic acid at varying amounts was added into the hydrogen production medium in order to have L-malic acid concentrations ranging from 0 to 4 g/l. Non-diluted and pre-diluted mediums with or without L-malic acid addition were also tested for comparison purpose (as controls). Prior to the hydrogen production experiments, all samples were subjected to pH adjustment, (pH 6.7) and sterilized by autoclave at 121^oC for 15 min. In regards to the experiments in which the effect of dilution of the effluent from dark fermentation was studied, it was observed that dilution of the effluent from dark fermentation resulted in much better hydrogen productions. Among the dilution rates used, the experiments operated with 1/5 dilution ratio produced the best hydrogen production (241 ml H₂/ g COD_fed). On the other hand, it was seen that the mixing the effluent with L-malic acid (0 - 4 g/l) at increasing ratios (studied from 0% L-malic acid up to 100% by volume in the mixture) had further positive effect and improved the hydrogen production. The bioreactors containing only L-malic acid media resulted in the best hydrogen production (438 ml H₂ / g COD_fed). It was found that, undiluted raw cheese whey wastewater effluent from dark hydrogen production reactor was not suitable for photo-fermentative hydrogen production. It was concluded that dilution of the feeding helps to reduce the nitrogen content and the volatile fatty acid content that might be otherwise harmful to the photo-heterotrophic organisms. The second conclusion that can be drawn is that cheese whey effluent should be mixed with L-malic acid rich co-substrates such as fruit juice processing effluents before fed into the photo-fermentation reactor. Finally, the two-stage H₂-producing process could be applied in remediation of lactose-containing industrial wastes, H₂ being used on-site, to reduce process costs via generation of electricity by the help of hydrogen fuel cells. (author)

[en] Purpose: Evaluation of the efficacy of whey protein as antioxidant against γ-irradiation induced oxidative stress and dyslipidemia in male rats. Method: Rats were divided into groups; group 1 (control), rats in group 2 & 3 were exposed to γ-irradiation 5 & 10 Gy respectively and rats in group 4 & 5 were orally administrated with whey protein after γ-irradiation. The antioxidant status (glutathione (GSH), Superoxide dismutase (SOD), catalase (CAT), total antioxidant capacity (TAC) and malondialdehyde (MDA), lipid profile (total cholesterol (TC), triglyceride (TG) and high-density lipoprotein (HDL) as well as the hematological parameters were determined. Results: γ-irradiation had depletion in GSH, SOD, CAT and TAC levels and elevation in MDA. Moreover, an increase in TC & TG coupled with decrease in HDL after γ-irradiation. The hematological parameters decreased after γ-irradiation. Treated rats with whey protein improved the antioxidant status and minimized the alterations of lipid and blood cells induced by γ-irradiation. Conclusion: whey protein has a positive effect on lipid and antioxidant status to minimize the oxidative stress due to exposure to γ-irradiation.

[en] Protein supplements are widely consumed by athletes and recreationally active adults to enhance training adaptation, performance, and muscle recovery. However, the popularity of these supplements has led to instances of adulteration with banned substances, including diuretics. Diuretics, typically used for medical conditions like hypertension and edema, are illicitly added to supplements to promote weight loss and mask other doping agents. Their presence poses significant health risks, including electrolyte imbalances and renal dysfunction, and contributes to doping violations in sports. Despite the critical need to monitor diuretic contamination in protein supplements, there is a noticeable gap in the literature regarding optimized extraction methods for these compounds. This study aims to evaluate the efficiency of various solvents in extracting diuretic compounds from protein supplements. By assessing the extraction recovery rates and optimizing the selection of solvents extraction, this research seeks to enhance the sensitivity, specificity, and accuracy of liquid chromatography tandem mass spectrometry (LC-MS/MS) analysis. This study investigates the extraction efficiency and matrix effects of methanol and acetonitrile for detecting diuretics in whey protein using Liquid-Liquid Extraction (LLE) coupled with LC-MS/MS. Different solvent compositions 100%, 70%, and 50% methanol (100M, 70M, 50M) and acetonitrile (100A, 70A, 50A) were evaluated to optimize recovery rates and minimize matrix interference. Results show that methanol consistently outperformed acetonitrile in recovering diuretic compounds from whey protein. At 100M demonstrated the highest average recovery rates (49.639% to 99.735%) with moderate signal enhancement and minimal suppression effects, indicating effective mitigation of matrix interference. Similarly, 70M maintained balanced matrix effects and reliable recoveries (46.976% to 94.492%), making it a robust alternative for diuretic analysis. In contrast, acetonitrile exhibited greater variability in matrix effects and lower recovery rates. For instance, 100A showed significant signal suppression (0.070% to 9.267%), suggesting limitations in solubilizing diuretics from whey protein. While 70A provided a more stable profile, it still showed variability (matrix effects from -44.539% to 29.493%) compared to methanol. The study highlights the critical role of solvent selection in minimizing matrix effects and ensuring accurate diuretic quantification in complex food matrices. Methanol’s superior solvating power and polarity contribute to its effectiveness in mitigating matrix interference compared to acetonitrile. This research provides valuable insights for analytical chemists and food scientists aiming to improve the accuracy and consistency of diuretic analysis in food matrices, thereby ensuring consumer safety and regulatory compliance. (author)

[en] The effect of carboxymethylcellulose (CMC) on the aggregation of formulation based on calcium caseinate, commercial whey protein (WPC), and a 1:1 mixture of soy protein isolate (SPI) and whey protein isolate (WPI) was investigated. Protein aggregation could be observed upon addition of CMC, as demonstrated by size-exclusion chromatography. This aggregation behaviour was enhanced by means of physical treatments, such as heating at 90 deg. C for 30 min or gamma-irradiation at 32 kGy. A synergy resulted from the combination of CMC to gamma-irradiation in Caseinate/CMC and SPI/WPI/CMC formulations. Furthermore, CMC prevented precipitation in irradiated protein solutions for a period of more than 3 months at 4 deg. C

[en] This investigation was carried out to study the possibility to utilize gamma irradiation to activate starter culture during incubation period and prolong the shelf-life of yoghurt. Starter culture of yoghurt was subjected to gamma irradiation with 10, 15, 20, 25, 30, 35, 40 and 45 Gy to activate the starter then yoghurt was made. Effect of irradiation dose on titratable acidity and the sensory evaluation of all samples were evaluated during incubation period. The obtained results indicated that the irradiation doses 30, 35 and 40 Gy activated the starter and caused significant decreased of incubation period from 4 h to 3.5 h while irradiation doses that less than 30 Gy and more than 40 Gy did not significantly effect. Yoghurt samples were subjected to gamma irradiation with 1.5, 2.5 and 3.5 kGy to prolong the shelf-life of yoghurt samples. The sensory, microbial and chemical properties of yoghurt samples were evaluated during cold storage. The obtained results indicated that the counts of total viable bacteria, molds and yeasts were decreased by applying gamma irradiation. Irradiation treatment caused significant decrease in acidity. The overall acceptability scores, total solid and ph value of all treatments were gradually decreased as the storage period proceeded while total nitrogen of all treatments was not affected. In addition, treatments of yoghurt with 1.5, 2.5 and 3.5 kGy prolonged the shelf-life to 20, 28 and 36 days as compared to 12 days for control treatment

[en] Chicken carcasses dipped in whey fermented by Streptococcus thermophilus, lactic acid solution or water and irradiated at 2.5 kGy by 60Co were evaluated for bacteriological quality on day 1, day-3 and at 3-day intervals for an 18-day storage (4 degrees C) period. Unirradiated carcasses treated similarly were used as control. Gram negative bacteria, Yersinia and Campylobacter counts were significantly (p0.01) lower in irradiated samples, but no significant (p0.05) differences were observed ammong the dipping solutions. Salmonellae were completely eliminated in irradiated samples. Whey fermented by S. thermophilus reduced the proportion of Salmonella contaminated carcasses from 67% to 20%. As evidenced by the bacterial counts the shelf-life was found to be 15 days for irradiated carcasses compared to about 6 days for the unirradiated samples

[en] Proteases are highly exploited enzymes in food, leather, detergent, pharmaceutical, diagnostics, waste management, silver recovery, healing of the wound, cosmetics, etc. Of all proteases, alkaline proteases produced by Bacillus species are of great importance in the detergent industry due to their high thermostability and pH stability. Submerged fermentation technique was employed for the production of Protease by Bacillus subtilis using cheese whey and skimmed milk broth followed by ammonium sulfate precipitation and molecular weight determination by SDS PAGE. Protease characterization showed that it has a maximum enzyme activity at pH 9, temperature 45°, incubation period 20 minutes and gelatin substrate is suitable in enzyme assay. (author)

No abstract available

[en] A procedure has been developed which allows precise determination of Ca isotope ratios in natural and organic samples such as bones, milk and other biological materials. In this study the procedure is used to determine Ca isotope ratios in modern dietary systems and to establish the potential of Ca isotopes as a paleodiet tracer by analysis of bones. Multi-sampling across a 5 cm portion of a red deer jawbone shows invariant Ca isotope ratios and suggests negligible isotopic effect during bone remodelling. The difference between Ca isotopes in red deer diet and bones from one location was 0.65 per mille , in agreement with a previous study of diet/bone offsets. Similar values for modern deer-bone δ^44/42Ca from four geographically diverse populations demonstrate that geological/environmental conditions do not cause large variability and suggest that diet is the major cause for variations in bone δ^44/42Ca. δ^44/42Ca of herbivore milk is found to be ∼0.5 to 0.6 higher than the corresponding diet. Modern human milk has a δ^44/42Ca of -1.15 (n = 4) and is isotopically the lightest material reported in this study. This suggests that, for these samples, a significant portion of Ca intake was from dairy sources, and that human milk has Ca which is, again, ∼0.6 per mille isotopically lighter than dietary Ca intake. Finally, Ca isotope ratios are presented from a variety of samples formed during fermentation processes (e.g., curds, whey, etc.) which indicate that these processes do not fractionate Ca isotopes significantly. Together, the data in this paper indicate that, because milk is an important dietary source of Ca with a distinctive signature, Ca isotope ratios should provide a tracer for past dairy consumption. A simplified model is outlined to demonstrate the ability to quantify dairy consumption by the analysis of Ca isotopes in bones