Background Autolysis in lactic acid bacteria promotes the release of intracellular enzymes involved in proteolysis, lipolysis and flavour formation during cheese maturation. Although camel milk is an important dairy resource in arid regions such as Algeria, its indigenous microbiota remains underexplored regarding technological traits such as autolytic capacity. Aim This study evaluated the autolytic potential and peptidoglycan hydrolase (PGH) diversity of indigenous LAB isolated from Algerian camel ( Camelus dromedarius ) milk and assessed their technological relevance for dairy fermentations. Methods Twenty‐two LAB strains were analysed. Autolytic activity was screened on substrate‐enriched solid media and quantified under buffered conditions. Principal component analysis (PCA) was applied to classify strains according to their autolytic profiles. Zymogram analysis was performed to detect active PGHs and determine their molecular profiles. Major Findings Strain‐dependent variability in autolytic activity was observed. PCA distinguished strains with high, moderate and low autolytic capacities. Lactococcus lactis DBH10, LCL and Lactiplantibacillus plantarum BH14 exhibited the highest autolytic activity. Zymogram analysis revealed several PGHs, including a predominant ~45 kDa lytic band in L. lactis , along with genus‐specific enzymatic patterns. These results highlight the diversity of cell wall hydrolases among camel milk LAB and their association with differential autolytic behaviour. Scientific and Industrial Implications Highly autolytic indigenous LAB strains identified in this study could be considered as potential candidates for use as starters or adjunct cultures in fermented dairy products, pending further evaluation. These findings also support the valorisation of indigenous camel milk microbiota in dairy biotechnology.
Background/Context Sucrose plays a critical role in ice cream stability by controlling colligative properties, phase equilibria and molecular mobility within the freeze‐concentrated matrix. Reducing sugar content is of growing industrial interest due to nutritional demands, but it poses significant technological challenges related to structural stability and shelf life. Aim This study investigated the effect of stepwise sucrose reduction (10–20%) on phase behaviour, thermal transitions and structural stability of cream ice cream during frozen storage. Methods Ice cream formulations with reduced sucrose levels were produced and analysed for total soluble solids, freezing behaviour, thermal properties and phase transitions. Key parameters included freezing point depression, crystallisation enthalpy, melting transitions and glass transition temperatures. Structural stability was inferred from thermal analyses and should therefore be interpreted as physicochemical rather than sensory stability. Major Findings Sucrose reduction decreased total soluble solids, weakening freezing point depression and increasing the fraction of freezable water. This shift altered phase equilibria, shifting the onset of ice crystallisation and modifying crystallisation enthalpy and melting transitions, indicating reorganisation of ice crystal structure. Changes in glass transition temperatures revealed alterations in the thermal response of the unfrozen phase. These changes were associated with sucrose reduction, although the underlying molecular mechanism could not be conclusively established from the present data. As a result, the matrix became structurally less stable. These results indicate increased molecular mobility within the freeze‐concentrated phase and a greater susceptibility of the frozen matrix to physicochemical destabilisation, greater susceptibility to ice crystal coarsening during storage. Scientific/Industrial Implications Sucrose reduction disrupts the thermodynamic and kinetic balance of frozen systems. While moderate sugar reduction is feasible, compensatory formulation and process strategies are required to maintain phase stability, control recrystallisation and ensure product quality and shelf life.
Background The microbial community composition of goat milk significantly influences its quality, safety and functional properties. High‐throughput sequencing studies have revealed substantial variability in microbial diversity estimates; however, findings remain inconsistent due to methodological and environmental heterogeneity. Objective(s) This review quantitatively synthesised microbial alpha diversity in goat milk using the Shannon index and presented a qualitative assessment of Lactobacillus relative abundance across production contexts. Methods Studies employing both culture‐independent and culture‐dependent methods were included following a comprehensive literature search. Heterogeneity was evaluated using the I 2 statistic, and publication bias was assessed with funnel plots, Egger's regression and the trim‐and‐fill method. Due to inconsistent reporting formats, Lactobacillus abundance data were synthesised narratively. Major Findings The pooled Shannon diversity index was 2.04, indicating moderate alpha diversity in goat milk. Very high heterogeneity ( I 2 = 92%) demonstrated strong context dependence across studies. Subgroup analyses indicated that geographic location, milk processing conditions and farm management practices contributed substantially to observed variability. Narrative synthesis revealed a wide range of Lactobacillus abundance, from dominance in certain breeds, regions and artisanal systems to low proportions in intensively managed systems. Scientific or Industrial Implications Microbial diversity in goat milk is highly context‐dependent and cannot be generalised across production methods. The presence of potentially pathogenic taxa underscores the necessity for rigorous hygiene protocols, standardised milk handling and consistent reporting frameworks to ensure both cross‐study comparability and product safety. Lactobacillus variation across systems presents opportunities for targeted strain selection in artisanal dairy fermentation. These findings highlight the need for standardised reporting frameworks. Future research should prioritise metagenomic approaches to explore the functional potential of these diverse communities for targeted probiotic development.
Background Skim milk microfiltration is essential for casein–whey separation, but performance declines due to fouling and membrane ageing, which can modify surface properties and reduce flux. Aim(s) This study examined how ageing affects fouling dynamics by identifying the main foulants, quantifying irreversible resistance and flux, and characterising membrane charge and wettability. Methods Industrial polysulfone membranes (0.1 μm) were sampled after 1 day, 10 days and at end of life (E.O.L.). Water flux and resistance were determined by resistance‐in‐series analysis; foulants by RP‐UPLC; surface chemistry by ATR‐FTIR; surface charge by streaming‐potential zeta potential; wettability by dynamic contact angle; and statistics by two‐way ANOVA with Tukey post hoc. Major Findings Irreversible resistance varied nonlinearly with membrane age, increasing from fresh membrane to 1 day (0.27–1.86 × 10 12 m −1 ), decreasing after 10 days (0.69 × 10 12 m −1 ) and reaching the highest level at E.O.L. (2.75 × 10 12 m −1 ). Fouling was dominated by β‐casein and α S1 ‐casein, with minor whey–protein contributions and low levels of lipid‐related components. FTIR showed increasing protein signals with age, while fouling shifted the surface towards a more positive charge, with isoelectric points around pH 4.5–4.7. Dynamic contact angle measurements indicated a more hydrophobic initial response for fouled membranes, especially at E.O.L.; however, contact angles generally decreased with contact time, suggesting that measured wettability reflected both foulant composition and hydration or wetting of the dried fouling layer. Scientific or Industrial Implications These findings support CIP strategies primarily targeted at protein removal, while also accounting for age‐related changes in membrane surface properties. Such strategies may improve flux recovery, maintain performance, extend membrane lifespan and reduce unnecessary chemical and water use in dairy microfiltration.
