Bacterial proteolysis of casein leading to UHT milk gelation: An applicative study

This experiment was conducted to evaluate the quality of existing ultra-high temperature (UHT) treated milk available in two selected town markets of Bangladesh. A total of 27 UHT milk samples from three different brandsPran Dairy (A), Aarong Dairy (B) and Farm Fresh (C) were collected from local markets at Mymensingh and Gazipur districts during the period of 1stSeptember to 29th November, 2014. Parameters studied in this experiment were organoleptic (flavour, consistency, colour and appearance), physic-chemical (specific gravity, acidity, total solids, solids-not-fat, fat, protein, lactose, and ash) and microbiological (Total Viable Count and Coliform Count). All the samples were similar in respect of color, flavor, taste and texture, and no significant difference was observed. However, significant differences were revealed (p<0.05) in case of specific gravity, acidity, total solids, solids-not-fat, and protein content. On the other hand, insignificant differences were found (p>0.05) in case of fat, lactose, and ash content. Total Viable Count and Coliform count were found to be nil in all the milk samples. Milk samples of Farm Fresh UHT milk were superior to other brands of UHT Milk in terms of contents of total solids (119.23±0.57 g/kg),fat (34.97±0.35g/kg), lactose (43.23±0.51g/kg), and ash (7.00±0.26g/kg). Though there were some fluctuations in all the parameters studied, all the milk samples conformed to the standard values for UHT milk, and in general all of the UHT milk samples studied in this experiment was of good quality.Bang. J. Anim. Sci. 2015. 44 (3):132-136

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Storage of ram semen in gelatin supplemented extender

Acta Agraria Debreceniensis ◽

10.34101/actaagrar/48/2444 ◽

2012 ◽

pp. 7-10

Author(s):

Csilla Budai ◽

István Egerszegi ◽

József Rátky ◽

András Kovács

Keyword(s):

Analysis Of Variance ◽

Light Microscope ◽

Egg Yolk ◽

Live Cells ◽

Intact Cells ◽

Uht Milk ◽

Liquid Storage ◽

Gelatin Concentration ◽

Semen Extender

The aim of our study was to examine how different gelatin concentrations affect ram semens viability in liquid storage at 5 oC for five days. Our hypothesis was if we add gelatin to the semen extender, than the viability of ram semen will be better in the extenders containing gelatin, than the control. We used two different semen extenders:1.5% UHT milk and 1.5% UHT milk + 5% egg yolk. We added 0; 0.5; 1.0; 1.5; 2.0% Dr. Oetker gelatin to the semen extenders. We stored the semen for five days at 5 oC and in every 24 hour we made sampling.We stained the smears with Kovács-Foote staining and evaluated them with light-microscope. We categorized the cells in five groups like: live and intact cells, live cells with injured acrosome, dead cells, live head with dead tail and live tail with dead head. We used one-way analysis of variance (ANOVA) to assign how gelatin concentration affects the number of the categorized cells. On the fifth day, the viability was the best in the following semen extenders: 1.5% fat UHT milk + 1.0% gelatin and 1.5% fat UHT milk + 1.5% gelatin, but it was not significant (p>0.05).

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Simultaneous Determination of C18 Fatty Acids in Milk by GC-MS

Separations ◽

10.3390/separations8080118 ◽

2021 ◽

Vol 8 (8) ◽

pp. 118

Author(s):

Meiqing Chen ◽

Yangdong Zhang ◽

Fengen Wang ◽

Nan Zheng ◽

Jiaqi Wang

Keyword(s):

Fatty Acids ◽

High Sensitivity ◽

Raw Milk ◽

Uht Milk ◽

Milk Samples ◽

Accuracy And Precision ◽

Different Temperatures ◽

Chromatographic Resolution ◽

Commercial Milk

The determination of C18 fatty acids (FAs) is a key and difficult aspect in FA profiling, and a qualified method with good chromatographic separation and high sensitivity, as well as easy methylation, is required. A GC-MS method was established to simultaneously determine C18 FAs in milk. To simplify the methylation protocol for milk samples, besides a base-catalyzation methylation (50 °C for 20 min), the necessity of an additional acid-catalyzation was also studied using different temperatures (60 °C, 70 °C, 80 °C, and 90 °C) and durations (90 min and 150 min). The results showed that the chromatographic resolution was improved, although three co-eluted peaks existed. The base-catalyzation was sufficient, and an additional acid-catalyzation was not necessary. The proposed method was validated with good sensitivity, linearity, accuracy, and precision, and then applied in determining C18 FAs in 20 raw milk and 30 commercial milk samples. UHT milk presented a different profile of C18 FAs from raw milk and PAS milk samples, which indicated that excessive heating could change the profile. Overall, the proposed method is a high-throughput and competent approach for the determination of C18 FAs in milk, and which presents an improvement in chromatographic resolution and sensitivity, as well as a simplification of methylation.

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Performance of cost-effective PET packaging with light protective additives to limit photo-oxidation in UHT milk under refrigerated LED-lighted storage condition

Food Packaging and Shelf Life ◽

10.1016/j.fpsl.2021.100773 ◽

2022 ◽

Vol 31 ◽

pp. 100773

Author(s):

Aili Wang ◽

Cheryl M. Stancik ◽

Yun Yin ◽

Jian Wu ◽

Susan E. Duncan

Keyword(s):

Cost Effective ◽

Storage Condition ◽

Photo Oxidation ◽

Uht Milk

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Alterations in the Fatty Acid Composition in Infant Formulas and ω3-PUFA Enriched UHT Milk during Storage

Foods ◽

10.3390/foods8050163 ◽

2019 ◽

Vol 8 (5) ◽

pp. 163 ◽

Cited By ~ 2

Author(s):

Luis Miguel Rodríguez-Alcalá ◽

María V. Calvo ◽

Javier Fontecha ◽

Leocadio Alonso

Keyword(s):

Fatty Acid ◽

Milk Fat ◽

Fatty Acid Content ◽

Daily Intake ◽

Fetal Life ◽

Milk Products ◽

Uht Milk ◽

Beneficial Effects ◽

Infant Formulae ◽

The Central Nervous System

ω3-polyunsaturated fatty acids (PUFA) are known to have several beneficial effects, such as preventing the occurrence of cardiovascular events in adults and improving the development of the central nervous system during fetal life and childhood. Dairy products enriched in PUFA are now available on the market and can help consumers to meet the ω3-PUFA daily intake recommendations. Although PUFA are prone to oxidation, little information exists regarding the alterations they undergo when products containing PUFA are stored. In this study, five infant formulae (IF) and five ω3-PUFA enriched Ultra High Temperature (UHT)-milk products were examined during storage at room temperature in terms of fatty acid (FA) composition and trans fatty acid (tFA) content until the end of shelf life by chromatography techniques. The IF included two follow-on formulae, two first-age formulae and a special medical purpose formula with different fat contents (from 2.6% to 27.7%). In the ω3-PUFA enriched UHT-milk products the milk fat was replaced by eicosapentanoic fatty acid (EPA) and docosahexaenoic acid (DHA) rich oils. The fatty acid content of all samples remained stable whereas some variations were observed for the tFA isomer content (p < 0.05) in the UHT-milk samples.

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