ORCID Profile
0000-0002-6811-5897
Current Organisation
Murdoch University
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Publisher: Elsevier BV
Date: 03-2020
DOI: 10.1016/J.FOODCHEM.2019.125532
Abstract: The objective of this study was to determine the β-CN phenotypes in cow milk collected from HF and cross-bred HF dairy cattle in Phu Dong, Vietnam. In total, 85 s les of raw milk were collected from 85 in idual cows. Beta-casein (β-CN) phenotypes in cow milk were determined using ultra-high performance liquid chromatography coupled to high resolution mass spectrometry (UHPLC-HRMS). The results showed that three β-CN variants A1, A2 and I were detected and identified in the milk s les. Five β-CN phenotypes A1A1, A1A2, A1I, A2A2 and A2I were found with percentages of 0.035, 0.400, 0.059, 0.482 and 0.024, respectively. The higher proportion of β-CN phenotype A2A2 compared to other phenotypes was expected because of changes in dairy cow breeding in Phu Dong, Vietnam.
Publisher: Elsevier BV
Date: 2021
Publisher: Informa UK Limited
Date: 31-07-2014
Publisher: Springer US
Date: 2022
Publisher: Elsevier
Date: 2017
Publisher: Elsevier BV
Date: 12-2015
Publisher: Elsevier BV
Date: 04-2018
DOI: 10.1016/J.FOODRES.2017.12.035
Abstract: Liquid chromatography-high resolution mass spectrometry (LC-HRMS) was used to investigate the degradation of β-casomorphin 5 (β-CM5) and β-casomorphin 7 (β-CM7) by Streptococcus thermophilus and/or Lactobacillus delbrueckii ssp. bulgaricus, and to identify the degradation products forming during yoghurt processing. Bovine UHT milk was fermented with: (i) a single strain of L. delbrueckii ssp. bulgaricus, (ii) a single strain of S. thermophilus and (iii) the mixture of S. thermophilus and L. delbrueckii ssp. bulgaricus to pH4.5 and then stored at 4°C for 1 and 7days. Results showed that L. delbrueckii ssp. bulgaricus and/or S. thermophilus completely degraded β-CM5 and β-CM7 upon fermentation to pH4.5 and degradation products were significantly influenced by bacteria strains and storage time. Four peptides, β-CNf60-61 (YP), β-CNf62-63 (FP), β-CNf64-66 (GPI) and β-CNf62-66 (FPGPI) were tentatively identified through high resolution MS/MS experiments however, it was not possible to confirm if either milk protein or β-casomorphins was a source releasing these peptides. Nonetheless, in this study peptides YP and GPI were released by L. delbrueckii ssp. bulgaricus. This is the first time GPI has been identified and thus future investigation of its bioactivity is warranted.
Publisher: Elsevier BV
Date: 03-2022
Publisher: Elsevier BV
Date: 03-2014
DOI: 10.1016/J.FOODCHEM.2013.09.057
Abstract: A highly selective and sensitive liquid chromatography-tandem mass spectrometry method was developed and validated for the simultaneous identification and quantification of beta-casomorphin 5 (BCM5) and beta-casomorphin 7 (BCM7) in yoghurt. The method used deuterium labelled BCM5-d10 and BCM7-d10 as surrogate standards for confident identification and accurate and quantification of these analytes in yoghurt. Linear responses for BCM5 and BCM7 (R(2)=0.9985 and 0.9986, respectively) was observed in the range 0.01-10ng/μL. The method limits of detection (MLDs) in yoghurt extracts were found to be 0.5 and 0.25ng/g for BCM5 and BCM7, respectively. Analyses of spiked s les were used to provide confirmation of accuracy and precision of the analytical method. Recoveries relative to the surrogate standards of these spikes were in the range of 95-106% for BCM5 and 103-109% for BCM7. Precision from analysis of spiked s les was expressed as relative standard deviation (%RSD) and values were in the range 1-16% for BCM5 and 1-6% for BCM7. Inter-day reproducibility was between 2.0-6.4% for BCM5 and between 3.2-6.1% for BCM7. The validated isotope dilution LC-MS/MS method was used to measure BCM5 and BCM7 in ten commercial and laboratory prepared s les of yoghurt and milk. Neither BCM5 nor BCM7 was detected in commercial yoghurts. However, they were observed in milk and laboratory prepared yoghurts and interestingly their levels decreased during processing. BCM5 decreased from 1.3ng/g in milk to 1.1ng/g in yoghurt made from that milk at 0day storage and <MLQ at 1 and 7days storage. BCM7 decreased from 1.9ng/g in milk to <MLQ in yoghurts immediately after processing. These preliminary results indicate that fermentation and storage reduced BCM5 and BCM7 concentration in yoghurt.
Publisher: Agricultural University Press
Date: 24-12-2019
DOI: 10.31817/VJAS.2019.2.3.03
Abstract: The objective of the study was to evaluate the effect of cow’s milk added to goat’s milk on physicochemical properties and sensory attributes of yoghurt. Yoghurts prepared from five different proportions of cow’s milk and goat’s milk were stored at 4-6ºC for 1, 7, and 14 days and then evaluated for their physicochemical (total solids, protein, pH, and acidity) and physical properties (viscosity and water holding capacity), and sensory characteristics (acceptability). The total solids of the evaluated yoghurts significantly increased, but the protein content decreased when the amount of cow’s milk increased in the mixtures of milk. The results showed that the pH value of the yoghurt made from only goat’s milk was higher, while the titratable acidity was lower than those of the yoghurts made from the mixtures of goat’s and cow’s milks. The yoghurt obtained from the mixture of milks containing 80% goat’s milk and 20% cow’s milk exhibited the highest viscosity and water holding capacity among the evaluated yoghurts. All the yoghurts received similar scores for color, odor, and texture after all periods of storage, while the highest score in terms of flavor was received for the yoghurt made from the mixture of milks containing 60% goat’s milk and 40% cow’s milk. Addition of cow’s milk to goat’s milk was shown to significantly contribute to the viscosity, water holding capacity, and flavor of the resulting yoghurts.
Publisher: Informa UK Limited
Date: 10-09-2020
Publisher: Springer Science and Business Media LLC
Date: 20-04-2017
Publisher: Elsevier BV
Date: 11-2019
Publisher: Oxford University Press (OUP)
Date: 03-2018
Abstract: This study investigated beta-casomorphin 7 (BCM7) in yogurt by means of LC-tandem MS (MS/MS) and enzyme-linked immunosorbent assay (ELISA) and use LC-MS/MS as the “gold standard” method to evaluate the applicability of a commercial ELISA. The level of BCM7 in milk obtained from ELISA analysis was much lower than that obtained by LC-MS/MS analysis and trended to increase during fermentation and storage of yogurt. Meanwhile, the results obtained from LC-MS/MS showed that BCM7 degraded during stages of yogurt processing, and its degradation may have been caused by X-prolyl dipeptidyl aminopeptidase activity. As a result, the commercial sandwich ELISA kit was not suitable for the quantification of BCM7 in fermented dairy milk.
Publisher: Elsevier BV
Date: 08-2019
Publisher: Agricultural University Press
Date: 05-06-2020
DOI: 10.31817/VJAS.2020.3.1.01
Abstract: The effects of frozen storage of goat’s milk on the physicochemical, physical properties, and sensory attributes of goat’s milk yoghurts were evaluated. Four yoghurts were made from goat’s milk stored at 4℃ overnight, and at -6, -20, or -35℃ for 1 month. Goat’s milk yoghurts were stored at 6℃ for 21 days. Protein and lipid contents in all the yoghurts were insignificantly different, however, the total solids content, including the added sugar in the yoghurts made from frozen goat’s milk, significantly increased in comparison with that in the yoghurt made from chilling goat’s milk. The water holding capacity (WHC) and viscosity for all the yoghurts at any period of cold storage were statistically different. No significant differences in pH or titratable acidity for all the yoghurts were observed after 1 day of cold storage however, these physicochemical properties for the yoghurts after 7 days of storage were significantly different. All the yoghurts after 21 days of storage received similar scores for appearance and texture, but significantly different scores for color, odor, flavor, and overall acceptability.
Start Date: 2018
End Date: 2020
Funder: National Foundation for Science and Technology Development
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