International Journal of Dairy Technology最新文献

The tolerance of 17 isolates of enterobacteria isolated from raw goat milk was evaluated against three sanitisers. All isolates were tolerant to sodium hypochlorite (1250 to >5000 ppm) and eight isolates were tolerant to peracetic acid (up to 1000 ppm). Two isolates were tolerant to all tested concentrations of quaternary ammonium with biguanide (>150/100 ppm). Although not all isolates are considered pathogens, they exert an important influence on the milk production chain. Sanitisers based on quaternary ammonium and biguanide seem to be more suitable for sanitisation in goat milk chain than sodium hypochlorite.

The effect of different thermal treatments including pasteurisation, ultra-pasteurisation, ultra-high temperature instantaneous sterilisation and in-container sterilisation on physicochemical properties and peptide profiles of infant formula protein model after in vitro digestion were investigated. Results indicated that different extent of protein–protein and protein–lactose interactions caused different particle size, colour, functional groups and thermal properties. Peptide profiles were also different after in vitro digestion. About 32, 4, 15, 157 and 42 unique peptides, as well as 14, 10, 12, 13 and 10 bioactive peptides were identified in the five groups, respectively. Pasteurisation may be better for the processing of infant formula.

The formation of the mammary secretion, proteins, lipids and ions is of fundamental importance to the dairy industry. The cellular interactions which allow secretion of protein and especially milk fat globules are still controversial. However, electron microscopy provides a basis for a straightforward scheme of secretion presented as a diagram. Each step in the process can then be defined, the published evidence for each assessed and areas which need further work clearly recognised. We also hope that the diagram will act as a way of combining global approaches such as proteomics or protein knockouts with the detail of electron microscopy.

Identifying the predominant strains of lactic acid bacteria (LAB) in dahi that are resistant to bacteriophages is essential for developing robust starter cultures. Dahi samples from two agroecological zones of Kerala were collected for isolation of LAB. Limosilactobacillus fermentum emerged as the dominant starter culture species based on sequence-based identification and technological property characterisation. Dairy effluents were screened for phages targeting L. fermentum, and 10 of 11 strains of L. fermentum showed resistance to one lytic phage isolated as part of this study. The strain ADMT 15 showed sensitivity to the phage and on subsequent genome sequencing the phage revealed its close relationship to members of the Herelleviridae phage family.

Biofilms generated during production of dairy/whey powders can cause contamination, spoilage and equipment failures, posing a significant challenge in the agri-food sector. Factors including temperature, protein composition, equipment structures and surface topography influence biofilm formation and resistance to cleaning and sanitation. Several species of bacteria are well adapted to these challenges, posing the most pressing concerns of dairy whey process. Despite efforts to improve cleaning-in-place strategies, bacteria persist in difficult-to-clean areas. This review provides insights into bacterial biofouling in dairy protein powders, highlighting the mechanism of biofilm formation, predominant bacterial genera, critical processing steps and strategies to manage biofilm formation during the manufacturing process.

Following the new standard of using plant-based ingredients, this study evaluated the effect of partially replacing milk proteins with plant proteins (almond and pumpkin seed) on yoghurt properties. Protein mixtures were prepared using rotational central composite design, investigating the percentage of animal protein replacement and the proportion between plant proteins. Milk protein substitution increased fermentation time, defined as the time needed to reach pH 4.6, and negatively impacted viscosity, firmness and syneresis of yoghurt. Nevertheless, replacing 25% of dairy proteins with an optimised plant protein blend (25% almond and 75% pumpkin seed) yielded yoghurt with typical composition and good sensory acceptance.

In developing nations, the widespread practice of adulterating milk with water, driven by economic motives, poses a significant threat to milk derivatives like yoghurt. Despite the absence of mandatory water detection tests for plain yoghurt, our study investigated the repercussions of adding 0–15% water to milk on plain yoghurt quality parameters over 28 days of refrigerated storage. Starter culture kinetics were notably affected, influencing colour and texture. Yet, sensory analysis indicated minimal impact on consumer perception. These results underscore the potential risk of unknowingly consuming adulterated yoghurt, emphasising the necessity for stringent regulatory measures to counteract such practices.