Sensory quality and consumer acceptance of skim yoghurt produced with transglutaminase at pilot plant scale

Optimizing Skim Milk Yogurt Properties: Combined Impact of Trans-glutaminase and Protein-Glutaminase

The lack of fat in yogurt can lead to alterations in taste and whey separation, reducing consumer acceptance. In this study, the feasibility of enhancing the quality of skim milk yogurt through a combination of transglutaminase (TG) and protein-glutaminase (PG) was investigated. The combination of TG and PG resulted in simultaneous cross-linking and deamidated of casein micelles, with PG deamidation taking priority over TG cross-linking, leading to higher solubility and lower turbidity of milk proteins compared with TG alone. When 0.06 U/mL TG and 0.03 U/mL PG were added, firmness and viscosity indexes significantly increased by 38.26 and 78.59%, respectively as compared with the control. Microscopic images revealed increased cross-linking with casein and filling of cavities by smaller sub-micelles in the combination of TG and PG treatment. Furthermore, the combination of TG and PG resolved issues of rough taste and whey separation, leading to improved overall liking. This study highlights the benefits of using both enzymes in dairy production and has important implication for future research.

Aroma-sensory properties of Gouda cheeses based on young Chinese consumers' preferences

The objective of this study was to examine the aroma profiles of 12 Gouda cheeses sold in China and to determine which aromas were preferred by young Chinese consumers (n = 110). The consumers selected 11 descriptors of the aromas of the Gouda cheeses in a check-all-that-apply questionnaire. These 11 descriptors were used by a panel of experts for sensory analysis to perform a quantitative descriptive analysis of the cheeses. A principal component analysis of the data from the quantitative descriptive analysis revealed that the characteristic aromas of young Gouda cheeses, medium-aged Gouda cheeses, and aged Gouda cheeses were "milky" and "whey"; "creamy" and "sour"; and "rancid" and "nutty," respectively. The results of a penalty analysis combined with the check-all-that-apply results and the preference scores showed that the 3 groups of young Chinese consumers (those who often ate cheese, occasionally ate cheese, and never ate cheese) preferred the Gouda cheeses with "milky" or "creamy" aromas and did not enjoy those with "sour" or "rancid" aromas. Occasional cheese eaters comprised the majority of the young Chinese consumers, and they were more tolerant of the Gouda cheeses with "whey" and "sulfury" aromas than those who often or never ate cheese. In addition, we identified a positive correlation between the consumers' preferences for the aromas of the Gouda cheeses and their willingness to pay for them. Overall, the results of this study should help promote the development of Gouda cheeses and associated products that meet the preferences of young Chinese consumers.

Encapsulation of Bifidobacterium bifidum by internal gelation method to access the viability in cheddar cheese and under simulated gastrointestinal conditions

The current study was conducted to elucidate the impact of encapsulation on the stability and viability of probiotic bacteria (Bifidobacterium bifidum) in cheddar cheese and in vitro gastrointestinal conditions. Purposely, probiotics were encapsulated in two hydrogel materials (kepa carrageenan and sodium alginate) by using an internal gelation method. Cheddar cheese was supplemented with unencapsulated/free and encapsulated probiotics. The product was subjected to physicochemical (pH, titrable acidity, moisture, and protein) and microbiological analysis for a period of 35 days of storage. Furthermore, the probiotics (free and encapsulated) were subjected to simulated gastrointestinal conditions. The initial probiotic count in cheese containing encapsulated probiotic was 9.13 log CFU/g and 9.15 log CFU/g which decreased to 8.10 log CFU/g and 7.67 log CFU/g while cheese containing unencapsulated probiotic initially 9.18 log CFU/g decreased to 6.58 log CFU/g over a period of 35 days of storage. The incorporation of unencapsulated and encapsulated probiotic affected the physicochemical, microbiological, and sensory attributes of the cheese. The encapsulated probiotic bacteria exhibited better survival as compared to unencapsulated probiotic. A 2.60 CFU/g log reduction in unencapsulated cells while just 1.03 CFU/g and 1.48 CFU/g log reduction in case of sodium alginate and K-carrageenan, respectively, was recorded. In short, encapsulation showed protection and stability to probiotic in hostile conditions.

Functional quality evaluation and shelf life study of synbiotic yacon juice

The research aimed to utilize the prebiotic potential of yacon fruit by preparation of synbiotic yacon juice containing probiotic microorganism Lactobacillus acidophilus (La5) and studying the changes in physicochemical properties during storage. The fresh juice extracted was added with probiotic microorganism and was subjected for storage at refrigerated (4°C) and room condition (25°C) along with control (nonfermented) juice. The viability of probiotic strains in the juice was found to be at the satisfactory level (106 CFU/ml) for 27 and 15 days, respectively, in refrigerated and room condition. Total soluble solid, pH, acidity, bioactive compounds (ascorbic acid, carotenoid content, and total phenol), and antioxidant capacity of the products were evaluated. Total soluble solid of the prepared synbiotic juice stored at refrigerated and nonrefrigerated conditions decreased from 7.8 ± 0.05 to 5.5 ± 0.26 and 5.3 ± 0.10 while the acidity increased from 0.067 ± 0.05 to 0.80 ± 0.06 and 1.02 ± 0.04 after 27 and 15 days of storage, respectively. Similarly, yeast and mold count, total plate count, and the coliform count were determined during the storage period. The low amount of yeast and mold count and absence of coliform in the synbiotic juice even after 27 and 15 days of storage indicated that the synbiotic juice can be continued to be consumed as a normal juice even after the viability decreased below the satisfactory level. Ascorbic acid, phenolic content, and antioxidant activity were higher in fermented juice when compared to control juice stored at the refrigerated conditions for the same period (p < .05). High therapeutic properties and numerous health benefits of yacon, when combined with the health benefits of probiotic bacteria, could lead to the development of commercial beverages with high health and nutritional values.