International Journal of Dairy Technology最新文献

Milk serves as a suitable medium for the growth of foodborne pathogens, including Candida albicans, which may possess virulence properties. Therefore, understanding the virulence characteristics and thermotolerance of C. albicans isolated from milk is important for ensuring safety and quality in the dairy industry. This study aims to identify Candida species in raw milk and detect thermotolerance and pH-changing features of C. albicans by indicating antifungal resistance, virulence and biofilm-forming capability via phenotypic and genotypic researching. Identification of Candida species and detection of antifungal resistance and virulence markers in C. albicans were carried out via Polymerase Chain Reaction. Thermal tolerance of C. albicans isolates was determined through microbial counts on specific parameters (63°C, 68°C and 72°C). Each experiment was replicated three times to ensure reliability. Post hoc analyses were performed to compare the observed differences. The prevalence of Candida albicans (15%), Candida parapsilosis (8%), Candida krusei (3%), Candida lusitaniae (2%) and Candida glabrata (1%) was revealed in 100 milk samples. C. albicans isolates exhibited significant virulence, antifungal resistance and biofilm-producing properties. Low-temperature long-time pasteurisation (63°C for 30 min) provided a 3.18 log reduction of C. albicans from an initial 4 log population, while high-temperature short-time pasteurisation (72°C for 15 s) resulted in a 0.83 log reduction. Determination of the thermotolerance of C. albicans with phenotypically and genotypically determined virulence properties will guide the optimisation of the pasteurisation process to prevent economic, safety and quality concerns in dairy industry. This investigation will also provide valuable insights into the scientific understanding of the dynamics of virulent C. albicans in milk and the efficacy of heat treatments in reducing its load.

The changes during a 4-month storage period at 5 or 25°C were investigated for sensory characteristics, volatiles and odorants of indirect (plate-type) ultra-high-temperature processed and aseptically filled milk. Quantitative descriptive analysis (QDA) showed that “plastic odour” and “smoothness” were stronger in the milk stored at 25°C for 2 and 4 months versus 5°C. Principal component analysis (PCA) of gas chromatography–mass spectrometry data revealed that the volatile profile change was larger at 25°C versus 5°C and that the storage duration at 25°C affected the volatile profile. Gas chromatography-olfactometry (GC-O) confirmed that similar changes were dependent on the storage temperature. A “coconut” odour contributed to the change in the odour profile. The QDA and GC-O results suggest that the increase in the “plastic odour” was a specific change associated with the 25°C stored milk and that (Z)-6-dodecen-4-olide, which had the strongest “coconut” odour, was related to the “plastic odour”.

Saturday, 13 July 2024, brought the sad news of the death of Professor Patrick Fanahan (P. F.) Fox, Professor Emeritus of Food Chemistry at University College Cork who had died on the previous day. Though he nominally retired in December 1997, he remained active in recent years, and his last book is with the publisher Oxford University Press. He was respected internationally as perhaps the leading dairy chemist of his generation and widely regarded as one of Ireland's most distinguished scientists of the 20th century.

Patrick Fox was born on 20 November 1937 and reared on a dairy farm near Mitchelstown, Co. Cork, the eldest of eight children. He was educated in the local national school, and later at secondary school in nearby Mitchelstown, where he was top of his class for his 5 years there. Though he probably would have taken up farming, he was encouraged by both his mother and his grandmother to go on to third-level education. Thus, he registered for the 4-year BSc (Dairying) degree course at University College Cork in October 1955. He qualified in the summer of 1959, with 1^st Class Honours.

He was interested in doing postgraduate studies in Microbiology and spoke to Professor Michael Grimes about this. However, Professor Grimes was about to retire and was not taking on any postgraduate students at the time, but suggested that he should speak to Professor Frank Kosikowski, Head of the Dairy and Food Faculty of Cornell University, who was a Fulbright Fellow in UCC in 1958–1959.

Professor Kosikowski arranged that he commence a PhD programme in Cornell University, Ithaca, in upstate New York in August 1959, majoring in Dairy Science, with minors in Biochemistry and Microbiology. Along the way, his focus and interest shifted from Microbiology to Chemistry. In 1964, it was felt that he had sufficient work done to start writing up his PhD thesis. When he presented his first draft to Kosikowski, the latter was far from impressed. He was told ‘You come from a country that has produced many famous writers, now go and emulate them’. This left a lasting impression and from then on Professor Fox aimed to do so, and with some success. He also passed on this advice to his own postgraduate students thereafter. Having completed his PhD in May 1964, he subsequently undertook postdoctoral research, under Dr Hans Lillevik, in Michigan State University, East Lansing (1964–1965), followed by further research with Dr Nick Tarassuk, in UC Davis (1965–1966). However, in January 1967 he decided to return to Ireland and joined the Dairy Technology Department of An Foras Talúntais (The Agricultural Institute), in Moorepark, Fermoy.

In 1969, Professor Gerald T. Pyne retired. He had served as lecturer and later professor of Dairy Chemistry from the foundation of the Dairy Science Faculty at University College Cork in 1924. There were six applicants for the position, which was now changed to professor of Dairy and Food Chemistry. Profe

Ultraviolet radiation (UV-C) is building a strong reputation as a non-thermal processing method in the food industry which inactivates spoilage and pathogenic microbes through DNA damage. Approved under Regulation (EC) No 258/97, UV-treated milk is deemed safe, with EFSA approving a dose of 1045 J/L post-pasteurisation, increasing vitamin D3 content and shelf life to 21 days. However, current verification relies solely on reactor process conditions, which may fail. Therefore, a verification method, akin to pasteurisation's alkaline phosphatase test, is essential. A process analytical technology sensor, analysing photooxidation-induced spectral changes, could ensure treatment efficacy. However, developing such sensors faces challenges from milk's optical properties (low UV transmission) and natural variability. Developing such sensor could pave the way for standalone UV-C treatment as a future environmentally friendly alternative. The objective of this study is to systematically document the challenges encountered to date in the investigation of this novel verification methodology.

The ice cream industry generates considerable waste due to stringent quality standards and food safety regulations, creating resource recovery opportunities. This study aimed to develop an efficient method for recovering high-purity fat from ice cream wastes using ethanol-induced emulsion destabilisation. Ice cream was treated with varying ethanol concentrations (0%–50% w/w in water) and incubated at different temperatures. Increased ethanol and temperature accelerated the separation of melted ice cream into phases (transparent liquid, continuous fat and opaque solid). Notably, 25% ethanol facilitated complete fat separation as a highly pure (>93%) phase, with the fat content exceeding 98% on a dry basis. Fat quality remained intact, as neither ethanol nor temperature affected fat hydrolysis or oxidation, based on peroxide value, free fatty acid levels and p-anisidine results. The recovered fat represented about 50% of the original fat content in the ice cream, reducing waste and enhancing by-product value.

The Dairy Academy 2024, an event held as a part of the EU Erasmus+ project ‘European Excellence in Dairy Learning’ (AEDIL Dairy CoVE), gathered 40 early career researchers with different backgrounds and from different career levels at the University of Copenhagen, Denmark on 24–28 June 2024. In the mornings, the participants engaged in interactive training sessions under the theme ‘Future Dairy Processing Challenges’, while in the afternoons, the online Dairy Science and Technology Symposium could be joined by everyone interested worldwide. On several evenings, social and networking events were offered to the participants. The event received highly positive feedback from the attendees and will be repeated with a new programme at the Agricultural University of Athens, Greece in 2025. The aim of this report is to provide a detailed summary of the summer school and symposium contents as well as an excerpt of the course evaluation to promote the upcoming Dairy Academies and inspire and guide future learning events and conferences.

Milk proteins are susceptible to denaturation and aggregation upon heating, affecting product quality and shelf-life. Understanding the underlying molecular changes during heating is important to the dairy industry for process optimisation and product functionality. This study used Attenuated Total Reflectance (ATR)-Fourier Transform Infrared (FTIR) spectroscopy to non-destructively measure changes in protein molecular structure as the precursor to heat-induced aggregation in milk. Raw skim milk was divided into three subsamples, adjusted to pH 6.2, native pH or pH 7. Each sample was heated at 85°C on a BioATR crystal, with scans taken at 1-min intervals over 20 min using FTIR to measure protein denaturation and aggregation. The second derivative of the amide I region was used to measure changes in protein structure, with the spectra for pH 6.2 samples changing faster than pH 6.8 or pH 7 samples, indicating a higher rate of denaturation. The peak at 1072 cm⁻¹ related to colloidal calcium phosphate (CCP) increased with increasing temperature and pH. More extensive changes in CCP between colloidal and serum phases and protein denaturation/aggregation correlated with lower heat stability in milk. This study highlights the potential of ATR-FTIR spectroscopy for assessing the heat stability of milk via in situ measurement of changes in protein structure and CCP.

In this paper, VOSviewer and CiteSpace were used to conduct bibliometric approaches to investigate the current trends (2010–2023) of ‘incorporation of polyphenol-rich ingredients in dairy products’. Given the diversity, bioactivity and accessibility of phenolic compounds, researches in this field have seen extensive global engagement and have been currently experiencing rapid growth. The improvements in antioxidant activity and stability of dairy products were topical beneficial effects of phenolic compounds. Moreover, antimicrobial properties and support for probiotic functions of phenolic compounds are critical factors driving their widespread application in the dairy industry. Additionally, there has been a significant interest in the interactions between phenolic compounds and proteins in dairy products as well. Furthermore, the attention on rheological property and sensory property might be rising in the upcoming years. This paper quantified and visualised the evolution of polyphenol-rich dairy products and provided insights into future trends.

Breast milk plays a crucial role in giant panda growth (Ailuropoda melanoleuca). This study aimed to analyse nutritional profiles in colostrum and mature milk. Based on DIA proteomics, the colostrum was rich in immunoreactive proteins, anti-inflammatory and antimicrobial proteins. The mature milk contained proteins involved in ribosome, fatty acid degradation and amino acid metabolism. Besides, there were more amino acids and saturated fatty acids in mature milk than colostrum. This research enclosed the nutritional difference in colostrum and mature milk of giant panda innovatively, and provided scientific evidence for exploiting substitutes that simulate natural breast milk for different lactation stages.

The physicochemical properties and in vitro digestion behaviours analysis of dairy matrices (liquid cow milk, semi-liquid yoghurt and semi-solid cheese) with different fat globules were evaluated. Yoghurt and cheese with large/small-sized fat globules were produced with raw (~4 μm) and homogenised cow milk (~0.40 μm). During the whole in vitro digestion, small-sized dairy matrices had a higher lipolysis degree (~70–83%) compared to large-sized ones (~55–77%) during the whole digestion. Small-sized dairy matrices showed greater in vitro proteolysis and more porous protein matrix compared to large-size ones. Dairy matrices with different fat globules exhibited different digestive behaviours, helping design lipid structures in different food matrices and their application in regulating digestive kinetics.