Effect of ultra high temperature processing and storage conditions on phenolic acid, avenanthramide, free fatty acid and volatile profiles from Australian oat grains

2018 ◽  
Vol 15 ◽  
pp. 21-29 ◽  
Author(s):  
Jasmeet Kaur ◽  
Andrew Whitson ◽  
John Ashton ◽  
Lita Katopo ◽  
Stefan Kasapis
Author(s):  
Otávio A. S. Ribeiro ◽  
Kely P. Correa ◽  
Mauricio O. Leite ◽  
Marcio A. Martins ◽  
Jane S. R. Coimbra

The fatty acid's contents of non-conform pooled human milk can be affected by different processing and storage operational conditions. Besides, the knowledge of changes in the human milk fatty acid profile can help indicate its use in a given storage period, according to each newborn's specific need. Thus, in the present work, changes in the fatty acid profiles of three types of human milk (raw; pasteurized at 62.5 °C for 30 min; homogenized at 40 oC for 30 s followed by pasteurization) were studied during storage for six months in a freezer at -18 oC. Large variations were observed in the concentrations of polyunsaturated fatty acids, particularly of docosahexaenoic acid, with a reduction of almost 50% of its total. Palmitic and stearic acid contents also changed according to the conditions of processing and storage. Correlations between the decrease of long fatty acid chains and the increase of medium and short chains were verified.  Thus, we observe that operational conditions of processing and storing change human milk lipid profile, with some nutritional losses.


1991 ◽  
Vol 54 (2) ◽  
pp. 109-112 ◽  
Author(s):  
R.K. HUTCHENS ◽  
A.P. HANSEN

Raw cream was standardized to 10% fat and processed by ultra-high-temperature (UHT) steam injection at 149°C for 20 s, 149°C for 3.4 s, 138°C for 20 s, and 143°C for 7 s, then aseptically packaged by a Tetra Pak AB3-250 filler. Packages were stored for 12 months at 24°C and analyzed at 0, 1, 3, 6, and 12 months. Fat-soluble carbonyls were extracted from the UHT cream with carbonyl-free hexanes and converted to their 2,4-dinitrophenyl-hydrazone derivatives. Alkanal hydrazones were separated by column chromatography into pure fractions. Spectrophotometry and gas chromatography were used to identify the alkanals. Butanal, hexanal, heptanal, nonanal, and decanal were identified and found to decrease in concentration during storage.


Molecules ◽  
2021 ◽  
Vol 26 (8) ◽  
pp. 2339
Author(s):  
So-Yul Yun ◽  
Jee-Young Imm

Age gelation is a major quality defect in ultra-high-temperature (UHT) pasteurized milk during extended storage. Changes in plasmin (PL)-induced sedimentation were investigated during storage (23 °C and 37 °C, four weeks) of UHT skim milk treated with PL (2.5, 10, and 15 U/L). The increase in particle size and broadening of the particle size distribution of samples during storage were dependent on the PL concentration, storage period, and storage temperature. Sediment analysis indicated that elevated storage temperature accelerated protein sedimentation. The initial PL concentration was positively correlated with the amount of protein sediment in samples stored at 23 °C for four weeks (r = 0.615; p < 0.01), whereas this correlation was negative in samples stored at 37 °C for the same time (r = −0.358; p < 0.01) due to extensive proteolysis. SDS-PAGE revealed that whey proteins remained soluble over storage at 23 °C for four weeks, but they mostly disappeared from the soluble phase of PL-added samples after two weeks’ storage at 37 °C. Transmission electron micrographs of PL-containing UHT skim milk during storage at different temperatures supported the trend of sediment analysis well. Based on the Fourier transform infrared spectra of UHT skim milk stored at 23 °C for three weeks, PL-induced particle size enlargement was due to protein aggregation and the formation of intermolecular β-sheet structures, which contributed to casein destabilization, leading to sediment formation.


1984 ◽  
Vol 47 (2) ◽  
pp. 105-107 ◽  
Author(s):  
BARBARA P. KEOGH ◽  
G. PETTINGILL

An investigation was undertaken into the relationship between the enzyme activity of cells harvested from raw milk and time taken for age gelation (TAG) to occur in the milk after ultra-high-temperature processing. It was shown that there was no relationship between the TAG and the bacterial counts on milk agar at 30°C or 7°C nor was there a relationship between the counts and the level of enzyme activity of the harvested cells. There was, however, a significant correlation between the level of enzyme activity of the harvested cells and the TAG. When extra bovine leucocytes were added to raw milk before processing, the TAG was increased. This suggested that there was an inhibitory action of leucocytes in development of age gelation.


2015 ◽  
Vol 4 (3) ◽  
pp. 56 ◽  
Author(s):  
Alexandr Ya Yashin ◽  
Boris V. Nemzer ◽  
Emilie Combet ◽  
Yakov I. Yashin

<p>Despite the fact that mankind has been drinking tea for more than 5000 years, its chemical composition has been studied only in recent decades. These studies are primarily carried out using chromatographic methods. This review summarizes the latest information regarding the chemical composition of different tea grades by different chromatographic methods, which has not previously been reviewed in the same scope. Over the last 40 years, the qualitative and quantitative analyses of high volatile compounds were determined by GC and GC/MS. The main components responsible for aroma of green and black tea were revealed, and the low volatile compounds basically were determined by HPLC and LC/MS methods. Most studies focusing on the determination of catechins and caffeine in various teas (green, oolong, black and pu-erh) involved HPLC analysis.</p> <p>Knowledge of tea chemical composition helps in assessing its quality on the one hand, and helps to monitor and manage its growing, processing, and storage conditions on the other. In particular, this knowledge has enabled to establish the relationships between the chemical composition of tea and its properties by identifying the tea constituents which determine its aroma and taste. Therefore, assessment of tea quality does not only rely on subjective organoleptic evaluation, but also on objective physical and chemical methods, with extra determination of tea components most beneficial to human health. With this knowledge, the nutritional value of tea may be increased, and tea quality improved by providing via optimization of the growing, processing, and storage conditions.</p>


2021 ◽  
Vol 51 (11) ◽  
Author(s):  
Joelson Sousa Lima ◽  
Ana Paula Presley Oliveira Sampaio ◽  
Mylla Christy da Silva Dufossé ◽  
Paula Fernanda Morais de Sousa ◽  
Josyane Brasil da Silva ◽  
...  

ABSTRACT: Buffalo milk is rich in nutrients and can serve as a substrate for the proliferation of microorganisms. Thus, the objective of the present study was to evaluate the growth kinetics of Salmonella Typhimurium and Listeria monocytogenes in buffalo milk under different processing and storage conditions. Samples of raw and pasteurized milk were inoculated with 1 CFU of each bacterium, separately and together, per 25 mL. After contamination, samples were stored at 8 °C or 37 °C, and bacterial counts were performed at 24, 48, and 168 h. In addition, the accompanying microbiota growth, pH, and the effect of these variables on the growth kinetics of microorganisms were monitored. The pathogens tested were able to proliferate under most conditions tested, reaching high titers throughout the experimental period. At 37 °C, there was a decrease in pH and an increase in the accompanying microbiota that interfered with the microbial growth curve. It was also observed that pasteurized milk subjected to 8 °C provided better conditions for the multiplication of bacteria. Therefore, it was concluded that care throughout the production chain, storage, and commercialization of milk must be adopted to guarantee the microbiological safety of this food.


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