International Dairy Journal最新文献

The functional properties of foods are closely related with its matrix. This study examined the impact of curcumin-fortified Lactobacillus helveticus MB2-1 fermented milk gel on the intestinal lipid digestion and bioaccessibility of curcumin through dynamic digestion method. The gel properties, microstructure, oil droplets stability, free fatty acid (FFA) release and curcumin bioaccessibility during digestion of the curcumin-fortified milk gels fermented by L. helveticus MB2-1 or tradition commercial starters (Streptococcus thermophilus and Lactobacillus bulgaricus) were investigated and compared. The curcumin-fortified L. helveticus MB2-1 fermented milk gel was found to present higher apparent viscosity, more thicker properties, and firmer texture, which affect the gastrointestinal digesta status together with the release of oil droplets and solubilized curcumin, promote lipid digestion as well as enhance the bioaccessibility of curcumin during digestion. These results may provide valuable references for the design of therapeutic dairy products beneficial to health in terms of food matrix.

The study aims to produce yoghurt from kefir beverage and evaluate its fermentation kinetics, volatile organic compounds, texture, and microbial characteristics. Kefir, a fermented milk product, is known for its health benefits due to probiotic microorganisms. To improve its sensory properties, kefir was combined with yoghurt starter cultures (Lactobacillus delbrueckii and Streptococcus thermophilus), sodium caseinate, and lactose, and incubated for 12 and 24 h. Comprehensive analyses were conducted on the obtained yoghurts, encompassing fermentation parameters (pH and acidity), volatile organic compounds, and textural properties. The levels and viability of specific microorganisms within the samples were examined through propidium monoazide quantitative PCR (PMA-qPCR). The results showed that samples with Na-caseinate had higher firmness, consistency, and cohesiveness. Viscosity increased with the addition of Na-caseinate and lactose after 24 h. PMA-qPCR analysis revealed higher microorganism levels in samples with Na-caseinate and lactose. Solid-phase microextraction (SPME) and gas chromatography–mass spectrometry (GC-MS) analysis showed that diacetyl was the most common compound, and acetaldehyde and diacetyl levels decreased in yoghurts compared to kefir beverages. PMA-qPCR revealed that Streptococcus thermophilus had higher viability in samples with both Na-caseinate and lactose, while Lactobacillus delbrueckii had the highest viability in samples that contained only Na-caseinate incubated for 12 h. The study suggests that kefir-based yoghurt can be developed into a product with better sensory qualities and increased consumer appeal due to improved texture and aroma.

This work proposes the use of Near Infrared Spectroscopy (NIR) and multivariate analysis to identify and quantify potential adulterants in grated hard cheeses. The study includes permitted additives (microcellulose and silicon dioxide) at levels higher than those regulated, as well as non-permitted substances like wheat flour, wheat semolina, and sawdust. An authentication approach was developed using One-Class Partial Least Squares (OC-PLS) and Data-Driven Soft Independent Modeling of Class Analogy (DD-SIMCA). Excellent results were obtained by DD-SIMCA using multiplicative scattering correction (MSC), projecting all unadulterated grated hard cheese samples within the acceptance area (i.e., 100% of sensitivity in both the training and test sets) and 77 out 80 adulterated samples outside the acceptance area (i.e., 96% of specificity in the test set). Additionally, satisfactory quantification results were obtained by Partial Least Squares (PLS) for the study of microcellulose, wheat flour, and sawdust, with root mean square error of prediction (RMSEP) values of 1.217, 1.317, and 0.562% w/w, R²_pred values of 0.945, 0.945, and 0.957, and relative error of prediction (REP) values of 4.285, 4.271, and 4.836%, respectively. The proposed methodology provides a simple, rapid, and low-cost analytical tool to identify and quantify adulterations in grated hard cheeses, with the aim to protect consumers from deceptive practices that compromise the nutritional quality of this widely consumed food.

This study utilized whey protein concentrate (WPC) as the primary protein source, employing the Maillard reaction to link it with three distinct carbohydrates: lactose, maltodextrin, and gum Arabic. Mixtures were prepared with a 1:4 protein-to-carbohydrate ratio, and conjugation was performed using dry heating at a temperature of 60 °C, 50% relative humidity for 8 h processing time. Under the same conditions, native WPC was heated as a control group. The formation of conjugates was tracked by monitoring absorbance changes, browning index (BI), and reduction in free amino groups (FAG). All conjugates exhibited significant loss of FAG, correlating with an increase in BI. Shifts in protein fingerprint bands observed via Fourier Transform Infrared Spectroscopy suggested potential protein-carbohydrate interactions, while X-ray diffraction showed increased sample crystallinity post-conjugation. Solubility assessments across pH levels (3.0–8.0) indicated a 10–13% rise in solubility for conjugated samples compared to mixtures, broadening their potential applications. Moreover, the emulsion stability index demonstrated improved stability after conjugation. Overall, the Maillard reaction-mediated conjugation enhanced the solubility and stability of emulsions.

In light of the growing production and consumption of functional foods, it is crucial to develop new methods to assess the authenticity of these products and prevent fraud and mislabeling. In this research, by integrating reverse transcription loop-mediated isothermal amplification (RT-LAMP) and the localized surface plasmon resonance (LSPR) effect of gold nanorods (GNRs), the viability of the probiotic bacteria has been evaluated. The RT-LAMP-GNR method effectively amplifies and identifies bacterial 16S-rRNA within 60 min. The efficiency of the RT-LAMP method was assessed by its implementation using RNA isolated from Lactobacillus acidophilus strain (L. acidophilus) and commercial probiotic yogurts. The method's limit of detection (LoD) was 10⁴ bacterial cells per ml, and its sensitivity was 10⁻⁵ ng/ml RNA.

Paneer is a fresh, non-melting, unripened cheese commonly consumed in South Asian countries. It is known for its mild flavor, firm texture, and high nutritional value. The manufacturing and compositional factors driving its production are complex and multifaceted. Beginning with the crucial function that, the composition and variety of the milk, and coagulating agents play in determining the texture and flavour characteristics of paneer, this review also includes a discussion on the importance of different pre-treatments of milk on the quality of paneer. The composition of milk varies depending on the source such as cow, buffalo, goat, camel, sheep and yak milk. The protein and fat content of milk varies depending on the type of milk, which affects the quality of the final product in terms of yield, taste and texture. The use of coagulant in the manufacturing of paneer is also an important factor affecting its yield and quality. The use of coagulants such as calcium lactone and galacto delta lactone was found to increase the yield of paneer. Paneer prepared using different coagulants was found to have different textural and organoleptic characteristics. The processing parameters and the pre-treatments are one of the principal factors that play an important role in paneer manufacturing. Pre-treatments such as High-pressure processing, pulsed electric field, homogenization, etc. have been found to significantly affect the quality characteristics of paneer. These techniques play an important role in reducing the microbial load of milk. Thus, review focuses on the effect of different varieties of milk, type of coagulant and pre-treatments on the yield and quality of the paneer.

Magnetic fields are a non-thermal food preservation method that applies short electrical pulses to kill harmful microbes while maintaining nutritional quality. Domiati cheese, manufactured from raw (DCR), pasteurized (DCP), magnetic (DCM), and magnetic-pasteurized (DCMP) cow milk and pickled over 90 days at room temperature. In addition, DCR was used as a control. Domiati cheese made from raw cow milk was kept as the control (DCR). The obtained results revealed that magnetic milk, compared to raw and pasteurized milk, had a higher pH value and a lower bacterial viability content, as well as free pathogenic bacteria. However, exposure to magnetic fields affected the color properties of cheese, there were significant increases in L* and a*, but decreased b* values were observed compared to other treatments. Domiati cheese made from magnetized milk (DCM) had the highest values of ripening factors. Total bacterial count values developed in all cheeses during pickling, then significantly decreased until the end. Pathogenic bacteria, mold & yeasts, and coliform groups were not detectable in DCM. It could be concluded that magnetic fields may be successfully applied in the manufacture of Domiati cheese, greatly improving the quality of Domiati cheese and increasing its shelf life.

Processed cheese is a dairy product made by heating and mixing natural cheese with emulsifying salts (sodium phosphates, polyphosphates, and citrates) to create a smooth and homogeneous cheese matrix. Adding emulsifying salts improves the emulsifying capacity of proteins (caseins), enhancing their ability to act as emulsifiers. Furthermore, processed cheese can contain various ingredients, focusing on nutrient content modification and techno-functional properties improvement, resulting in a final product with the desired properties. This review paper provides a comprehensive point of view of the existing information regarding emulsifying salt applications in manufacturing processed cheese and their impact on processed cheese quality and techno-functional properties. In particular, the ion exchange phenomenon, pH adjustment and stabilization, and creaming processes were detailed for solely applied emulsifying salts, and their binary and ternary mixtures. The prospects of emulsifying salts replacement were also considered. Generally, processed cheese's consistency (evaluated in terms of textural and rheological parameters) depends on the composition of emulsifying salts mixtures (ratios of sodium monophosphate, sodium diphosphate, sodium polyphosphate, and sodium citrate). The information summarized in this review could serve as a tool for the dairy industry to help appropriately select emulsifying salts for manufacturing processed cheese with desired properties. Future perspectives on emulsifying salt usage in processed cheese could include evaluating their role in improving nutritional profiles, enhancing functional properties, and addressing specific dietary requirements.

The aim of this study was to identify the microbiota of ovine bulk-tank milk (BTM) and monitor its changes during storage at 4 °C or 8 °C for 2 or 4 days, simulating BTM holding times at the farm and/or the processing facility prior to milk processing, by using high-throughput sequencing of the 16S rRNA gene. The results showed that the microbiota is comprised of a plethora of taxa present in low abundance. The core microbiota consists of 28 bacterial genera with Staphylococcus being the most abundant at the time of sampling. Pseudomonas spp. exhibited the highest mean relative abundance at the end of all storage schemes, except for 2 days of storage at 4 °C. Sheep milk can be stored at 4 °C for 2 days without compromise in its microbiological quality, whereas milk storage at 8 °C for 2 days was almost equivalent to storage at 4 °C for 4 days.

The calcium binding to enriched α_s1-casein (71 % α_s1-casein on a protein basis) that was native or dephosphorylated to different extents was studied using a calcium ion selective electrode and at an ionic strength comparable to that found in milk. The calcium binding to α_s1-casein decreased as the level of dephosphorylation was increased. Langmuir adsorption modelling of the calcium binding gave the maximum calcium binding and calcium binding affinity for the native α_s1-casein and progressively dephosphorylated α_s1-casein. This evaluation indicated that the number of calcium binding sites on α_s1-casein decreased as dephosphorylation increased; however, the affinity for any remaining calcium binding sites was unchanged. Correlations were observed between calcium binding of native and dephosphorylated α_s1-casein with the calculated charge at pH 7.0, or the calculated or experimentally determined isoelectric pH of the α_s1-casein. Understanding the calcium binding to native and dephosphorylated α_s1-casein is important in understanding casein association in systems such as natural and artificial casein micelles.