查看更多>>摘要：Effects of heating temperature, pH and salt addition (NaCl, CaCl2, citrate) on the heat stability of caprine micellar casein concentrate (MCC) dispersion were studied, and a simultaneous comparison with bovine MCC is provided. Heat stability of caprine MCC was lower than that of bovine MCC. Ca-ion activity was higher for caprine MCC compared with bovine MCC. Serum kappa-casein amount was higher for caprine MCC compared with bovine MCC, and increased with increasing pH, but decreased after heating. Ratio of kappa-casein in sediment was lower for caprine MCC. Casein micelles in caprine MCC had larger particle sizes and were more susceptible to aggregation. Internal structure of micelles was barely affected after heating. The poor heat stability of caprine MCC compared with bovine MCC might be attributed to the higher Ca-ion activity and more extensive dissociation of kappa-casein. Adding citrate and limited amounts of NaCl improved the heat stability of MCC. (C) 2022 Elsevier Ltd. All rights reserved.
查看更多>>摘要：Lipid and protein oxidation and the sensory properties of grated Kefalotyri cheese, produced during April and December with milk from pasture-grazing sheep, stored at 4 degrees C for 4 months, under modified atmosphere (MAP) or vacuum (VA) conditions and fluorescent light, were examined. By the end of storage, monounsaturated and polyunsaturated fatty acids were found to be significantly decreased in April and December cheeses, while no significant difference was detected between MAP and VA conditions. Lipid hydroperoxide and malondialdehyde determinations showed that lipid of April and December cheese was oxidised during MAP or VA storage, but significantly higher in April cheese. Evaluation of carbonyl changes showed that protein oxidation of the April cheese was significantly lower than December cheese. By the third month of storage, carbonyls for April and December MAP cheese were significantly lower than respective VA cheese. April and December MAP cheese presented better organoleptic characteristics than VA cheese. (C) 2022 Elsevier Ltd. All rights reserved.
De Pascale, SabrinaCaira, SimonettaGarro, GiuseppinaMauriello, Rosalba...
12页
查看更多>>摘要：A combination of chromatographic, immunoelectrophoretic and mass spectrometric methods was applied to healthy individual milk of ovine massese breed. Caseome of alpha(S1)-casein (alpha(S1)-CN) fraction was characterised in homozygous and heterozygous phenotypes for the novel B and G genetic variants. Using ovine alpha(S1)-CN C counterpart as reference, amino acid substitutions and phosphorylated components were determined. The replacement of p.Arg90 > His and p.Ile194 > Thr were found in alpha(S1)-CN B variant, while the single p.Ile194 > Thr substitution occurred in alpha(S1)-CN G variant. The quali-quantitative composition of phosphorylated alpha(S1)-CN components in milk of animals bearing each variant was defined, highlighting possible genetic markers for assessment of dairy product quality. The heterogeneity of the electrophoretic profiles of the corresponding caseomes was due to the number of phosphorylated components and their net charge and pI values, and updated the ovine alpha(S1)-CN phylogenetic tree, suggesting alpha(S1)-CN G as the ancestral variant of alpha(S1)-CN B and other variants. (C) 2022 Elsevier Ltd. All rights reserved.
Liu, DasongYuan, JiajieRegenstein, Joe M.Zhou, Peng...
10页
查看更多>>摘要：Texture and microstructure of high-protein yoghurts manufactured from milk protein concentrate (MPC) fortified skim milk heated at different temperatures (75, 80, 85, 95 degrees C for 10 min) and pH (6.5, 6.7, 6.9, 7.1) were studied. Whey protein (WP) denaturation increased from 16% to 89% with increasing heating temperatures, while WP binding to casein micelles decreased from 95% to 21% with increasing heating pH. Gelation pH during fermentation increased with increasing heating temperatures and pH. Gel network became denser when heating temperatures and pH increased. Firmness and coagulum particle size of yoghurts increased with increasing heating temperatures and pH. Water-holding capacity reached above 87%, and increased slightly with increasing heating temperatures and pH, followed by slight de-creases during storage. Reducing heating temperatures and pH of milk base offers potential strategies to obtain a desirably smooth texture without excessive syneresis for high-protein yoghurts manufactured by concentration before fermentation. (C) 2022 Elsevier Ltd. All rights reserved.
查看更多>>摘要：Rapid screening and early warning of pathogenic bacteria in food is the key to prevent and control the spread of foodborne diseases. Biotinestreptavidin system and membrane filtration technology were combined to develop a novel nuclear magnetic resonance (NMR) immunosensor based on biomacromolecule O-carboxymethyl chitosan (O-CMCS) target gadolinium (Gd) probe for rapid detection of Salmonella anatum in milk. Under optimal experimental parameters, the proposed NMR immunosensor could detect Salmonella in milk with a limit of detection of 1.8 x 10(4) cfu mL(-1) within 2 h. Furthermore, the immunosensor exhibited good specificity, sensitivity and reproducibility, which could achieve the direct determination of biological samples with complex composition. Hence, the developed assay might have great application potential for the rapid detection of Salmonella in food.(C) 2022 Elsevier Ltd. All rights reserved.
查看更多>>摘要：The combined effect of g-irradiation (5 kGy) and four antimicrobial formulations developed for their antimicrobial properties (1, Oregano/Mediterranean formulation/Citrus extract/Lactic acid; 2, Cinnamon/ Lemongrass/Citrus extract/Citric acid; 3, Oregano/Mediterranean formulation/Citrus extract/Citric acid); 4, Cinnamon/Lemongrass/Citrus extract/Lactic acid) was investigated in terms of microbial inactivation of selected foodborne pathogens, lactose and immunoglobulin composition, in vitro protein digestibility, peptide profile, physicochemical properties of mothers' milk in frozen condition. g-Irradiation treatment along with formulation 3 and 4 eliminated all tested pathogens including sporulated Bacillus cereus that was resistant to gamma-irradiation in the presence of formulation 1 and 2. Furthermore, combined treatment did not significantly alter the lactose, immunoglobulins and lipid oxidation of mothers' milk. Protein digestibility increased in the irradiated milk and hydrolysis of larger proteins to smaller peptides was demonstrated. Irradiated samples had a minimal change in colour and viscosity. Hence, combined treatment was effective in preservation of the quality of frozen mothers' milk. (c) 2022 Elsevier Ltd. All rights reserved.
查看更多>>摘要：Flaxseed is an excellent source of fibre, protein, and omega-3 fatty acids. Studies have shown its effectiveness in improving yoghurt texture; however, it has adverse effects on sensory properties. This study investigated the prospect of substituting flaxseed powder in its non-mucilage form to produce tasty functional stirred yoghurt. Four yoghurt groups were produced without stabiliser or with (at 3%, w/w) commercial stabiliser, mucilage-free flaxseed powder, or whole flaxseed powder. Microbial, chemical, physical, and sensory properties of samples were analysed weekly during 21 days of storage at 4 degrees C. Replacing the flaxseed powder with its mucilage-free form can preserve the physicochemical properties and prevent adverse changes in yoghurt flavour usually caused by flaxseed. It can also improve fatty acid profile (increasing polyunsaturated fatty acids, reducing the saturated fatty acids and omega 6/omega 3 ratio) of yoghurt. Using 3% mucilage-free flaxseed powder is suggested to enhance overall quality and nutritional value of yoghurt. (C) 2022 Elsevier Ltd. All rights reserved.
查看更多>>摘要：Changes in physicochemical parameters and composition of Bactrian camel milk were evaluated at 1, 7, 21, 35, and 90 days postpartum. Bactrian camel milk contained 14.82% total solids (TS), 10.89% solid nonfat (SNF), 5.96% lactose, 4.73% protein, 3.88% fat, and 0.88% ash on average in an apparent negative trend. Density and refractive index (RI) volatility decreased as lactation progressed (pH increased 21 days postpartum, following a decrease) with a relatively stable decline in freezing point, electrical conductivity (EC), and acidity. The amino acid profile declined in relative proportions as lactation processed, represented mainly by leucine and glutamic acid, and methionine, cysteine, and glycine to a lesser degree. The fatty acid profile, predominated by C18:1n9c, C16:0, and C14:0, changed according to the lactation stages, especially the highest unsaturated fatty acids on 1st day. Understanding the physicochemical indicators and composition represents the basis for research and development of Bactrian camel milk. (c) 2022 Published by Elsevier Ltd.
查看更多>>摘要：Ultrasound (US) treatment of milk is one of several emerging technologies, often promoted as nonthermal, although a combination with heat appears to show greater potential. Bacteriocidal effects have been studied, as well as certain interesting chemical and physical changes occurring as a result of this treatment. Comparison of published results is confounded by the lack of standardised treatment parameters. US does not appear to offer advantages regarding microbiological quality, in comparison with conventional HTST pasteurisation (72 degrees C for 15 s). Most publications do not address possible sensory changes caused by US treatment but, according to some authors, some definitive changes do occur. To obtain knowledge that ensures that quality products are produced, research on US is needed that combines the aspects of the effect on microorganisms, product functionality and quality and the influence on flavour and sensory aspects of the milk or milk product. (c) 2022 The Author(s). Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).
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