Low Fat Yoghurts Produced with Different Protein Levels and Alternative Natural Sweeteners.

The food industry is looking for substitutes for sucrose in food items due to the excessive consumption of products with added sugar and the demand for healthier products. Alternative natural sweeteners can help achieve this goal. Different types of low-fat yoghurts (1% fat), with low-protein and high-protein levels (3% and 4.5-6.5% protein, respectively), were produced using alternative natural sweeteners. The low-protein yoghurts were made with stevia (0.03% w/w) or agave syrup (4.5% w/w). The high-protein yoghurts were made with stevia (0.04% w/w), xylitol (6% w/w) or honey (6% w/w). Sucrose (6% w/w) was used as a control in both trials. pH and titratable acidity, CIEL*a*b* color parameters, syneresis index, rheology and the texture profile of the low-fat yoghurts were evaluated over refrigerated storage. All products underwent sensory evaluation by an untrained panel. The high-protein yoghurts were found to be more acidic (>1% as lactic acid), had a lower syneresis index (between 2.1 and 16.2%) and a better consistency (stronger gel structure) than the low-protein yoghurts. In terms of rheological parameters, stevia-sweetened yoghurts scored higher than the other sweetened yoghurts, showing a better gel structure. The different sweeteners tested did not significantly affect the sensory properties of the yoghurts, although the high-protein yoghurts scored higher for most of the attributes evaluated. Overall, consumers preferred stevia-sweetened yoghurts to yoghurts sweetened with sucrose or agave for the low-protein yoghurts. Of the tested formulations, those containing high protein with the alternative natural sweetener xylitol received higher scores in all attributes. These results reveal the potential of the tested natural sweeteners as sucrose substitutes, while contributing to improving the nutritional value of yoghurts.

Exploring the textural dynamics of dairy and plant-based yoghurts: A comprehensive study.

The mouthfeel and texture of dairy and non-dairy yoghurts play a critical role in food acceptance and liking. The present study aimed to understand the oral perception of commercially available dairy and non-dairy yoghurts. Four dairy and four non-dairy yoghurts with different levels of protein and fat were analyzed to understand the impact of particle size, textural properties and frictional coefficient on the dynamic sensory mouthfeel characteristics measured by the temporal dominance of sensations (TDS) method. Differences in friction coefficients of dairy and non-dairy yoghurts were observed. The friction factor was lower for high-fat dairy yoghurts than for non-dairy yoghurts. The particle size d90 in yoghurts was positively related to graininess perception (r=0.81) and negatively associated with mouthfeel liking (r=-0.87) and overall liking (r=-0.80). For the TDS results, "creaminess" and "thickness" were significantly dominant for dairy yoghurts, while "melty" and "easy to dissolve" were dominant attributes for non-dairy yoghurts. Creaminess perception improves the mouthfeel liking (r=0.72) and overall liking (r=0.59) of yoghurts and is the driver of liking. The findings of this study help understand the intrinsic mouthfeel properties of commercial dairy and non-dairy yoghurts, which will provide valuable insight to product developers during the new product formulation.

Probiotic Yoghurt Enriched with Mango Peel Powder: Biotransformation of Phenolics and Modulation of Metabolomic Outputs after In Vitro Digestion and Colonic Fermentation.

This study investigated the health-promoting effects and prebiotic functions of mango peel powder (MPP) both as a plain individual ingredient and when incorporated in yoghurt during simulated digestion and fermentation. The treatments included plain MPP, plain yoghurt (YA), yoghurt fortified with MPP (YB), and yoghurt fortified with MPP and lactic acid bacteria (YC), along with a blank (BL). The identification of polyphenols in the extracts of insoluble digesta and phenolic metabolites after the in vitro colonic fermentation were performed employing LC-ESI-QTOF-MS2. These extracts were also subjected to pH, microbial count, production of SCFA, and 16S rRNA analyses. The characterisation of phenolic profiles identified 62 phenolic compounds. Among these compounds, phenolic acids were the major compounds that underwent biotransformation via catabolic pathways such as ring fission, decarboxylation, and dehydroxylation. Changes in pH indicated that YC and MPP reduced the media pH from 6.27 and 6.33 to 4.50 and 4.53, respectively. This decline in pH was associated with significant increases in the LAB counts of these samples. The Bifidobacteria counts were 8.11 ± 0.89 and 8.02 ± 1.01 log CFU/g in YC and MPP, respectively, after 72 h of colonic fermentation. Results also showed that the presence of MPP imparted significant variations in the contents and profiles of individual short chain fatty acids (SCFA) with more predominant production of most SCFA in the MPP and YC treatments. The 16s rRNA sequencing data indicated a highly distinctive microbial population associated with YC in terms of relative abundance. These findings suggested MPP as a promising ingredient for utilisation in functional food formulations aiming to enhance gut health.

Tamarillo Polyphenols Encapsulated-Cubosome: Formation, Characterization, Stability during Digestion and Application in Yoghurt.

Tamarillo extract is a good source of phenolic and anthocyanin compounds which are well-known for beneficial antioxidant activity, but their bioactivity maybe lost during digestion. In this study, promising prospects of tamarillo polyphenols encapsulated in cubosome nanoparticles prepared via a top-down method were explored. The prepared nanocarriers were examined for their morphology, entrapment efficiency, particle size and stability during in vitro digestion as well as potential fortification of yoghurt. Tamarillo polyphenol-loaded cubosomes showed cubic shape with a mean particle size of 322.4 ± 7.27 nm and the entrapment efficiency for most polyphenols was over 50%. The encapsulated polyphenols showed high stability during the gastric phase of in vitro digestion and were almost completely, but slowly released in the intestinal phase. Addition of encapsulated tamarillo polyphenols to yoghurt (5, 10 and 15 wt% through pre- and post-fermentation) improved the physicochemical and potential nutritional properties (polyphenols concentration, TPC) as well as antioxidant activity. The encapsulation of tamarillo polyphenols protected against pH changes and enzymatic digestion and facilitated a targeted delivery and slow release of the encapsulated compounds to the intestine. Overall, the cubosomal delivery system demonstrated the potential for encapsulation of polyphenols from tamarillo for value-added food product development with yoghurt as the vehicle.

A Cross-Sectional Audit of Nutrition and Health Claims on Dairy Yoghurts in Supermarkets of the Illawarra Region of New South Wales, Australia.

Health and nutrition claims are used by consumers to guide purchasing decisions. In consequence, monitoring and evaluation of such claims to ensure they are accurate and transparent is required. The aim of this study was to investigate the use of nutrition and health claims on dairy-yoghurt products within select Australian supermarkets and assess their compliance with the revised Food Standards Code (FSC). Nutrition, health, and related claims on yoghurt products were assessed in a cross-sectional audit of five supermarkets in the Illawarra region of New South Wales. Claim prevalence, type, and compliance were assessed and products were compared against current rating measures. A total of n = 340 dairy yoghurt products were identified. Most products (97.9%) carried at least one nutrition and/or health claim, with nutrition-content claims (93.9%) the most prevalent. Most products (n = 277) met the nutrient profiling scoring criterion; while 87.9% of products did not carry the health star rating. Almost all claims surveyed (97.4%) were compliant with the FSC. Health and nutrition claims are highly prevalent across yoghurt categories, with the majority of these compliant with regulations. The ambiguity surrounding the wording and context of claims challenges researchers to investigate consumers' interpretations of health messaging within the food environment.

Physicochemical, microbiological, and sensory characteristics of probiotic Bulgarian yoghurts obtained by ultrafiltration of goat's milk.

The purpose of this study was to investigate the microbiological (number of viable lactic acid bacteria and bifidobacteria), physicochemical (dry matter, protein and fat contents, titratable acidity, and pH), and sensory characteristics (appearance of coagulum, taste and aroma, structure at cutting, color, and consistency at shattering) of probiotic Bulgarian yoghurts obtained by ultrafiltration of goat's milk. These yoghurts were obtained using volume reduction ratios of 2 and 3 with the probiotic starters MZ2f, MZ2f + Bifidobacterium bifidum BB - 87, and MZ2f + Lactobacillus acidophilus LAB - 8. The increase in the level of the concentration by ultrafiltration led to an increase in the dry matter, protein and fat contents of the yoghurts, in the number of lactic acid bacteria and titratable acidity, and to a decrease in the pH. The twofold concentration by ultrafiltration resulted in a higher number of lactic acid bacteria in comparison with yoghurts made without ultrafiltration, and with better sensory characteristics compared to yoghurts without and with threefold ultrafiltration. The higher number of viable cells and better sensory characteristics were obtained for yoghurts with MZ2f + Bifidobacterium bifidum BB - 87 and MZ2f + Lactobacillus acidophilus LAB - 8 in comparison with MZ2f alone.

Carmines (E120) in coloured yoghurts: a case-study contribution for human risk assessment.

Carmines (E120) are used worldwide as natural food colouring agents of animal origin, with a widespread application, including yoghurts. Despite being considered safe for human health, carmines are known to cause allergic reactions. Our goal was to evaluate the presence of carmines in different yoghurts with a label declaration of E120, purchased in Portugal, and, for the first time, to assess the human risk. The analytical methodology, recommended by JECFA, was based on acid hydrolysis of the samples followed by spectrophotometric UV-Vis analysis at 494 nm. This methodology allowed for a limit of quantification (LOQ) of 39.0 mg/kg and recovery rates higher than 97.7%. All the samples had carmines at levels above the LOQ, ranging between 43.8 and 193.8 mg/kg, with an average of 125.2 ± 34.5 mg/kg. In total, 8 (26.7%) samples exceeded the European Union (EU) maximum permitted level (MPL) established for carmines in this foodstuff, 150 mg/kg. Solid yoghurts presented higher average levels, 137.2 mg/kg, when compared to liquid samples, 107.2 mg/kg, with a significant statistical difference (p= 0.0236) being observed. No significant statistical difference was observed between white and private labels, whose average levels were very similar, 125.4 vs 125 mg/kg, respectively. Although some samples were above the allowable values, the estimated daily intake (EDI), designed for the different scenarios of different yoghurt types, did not exceed the established ADI, 5 mg/kg bw/day. According to the obtained results, carmine ingestion through the consumption of yoghurt poses low risk to the Portuguese consumers. However, children were the most vulnerable population group with a calculated risk value of up to 10% considering the mean content scenario. These first findings point out the need to reinforce surveillance programmes and monitoring studies, contributing to an increased awareness regarding carmine exposure, however it must be emphasised that yoghurt has evident nutritional benefits depending on a healthful consumer choice.

Síndrome urémico hemolítico y yogur: entre la creencia popular y la evidencia científica / Hemolytic uremic syndrome and yoghurt: popular belief and scientific evidence

Algunos profesionales de la salud desaconsejan el consumo del yogur por el riesgo de provocar Síndrome Urémico Hemolítico, una enfermedad grave causada por cepas de E. coli productor de toxina Shiga (STEC por sus siglas en inglés). Estas bacterias pueden pasar del intestino del ganado vacuno a la carne o a la leche en condiciones inadecuadas de trabajo en frigoríficos o establecimientos productores de leche, respectivamente, siendo las hamburguesas insuficientemente cocidas el principal vector de la enfermedad y la leche cruda sin pasteurizar o los productos lácteos elaborados con ésta, otro factor de riesgo. En la industria láctea, el yogur se elabora con leche que es sometida a un doble tratamiento térmico. En la bibliografía moderna reportes de la presencia de STEC en yogures industriales, y los trabajos de revisión y meta-análisis no incluyen al yogur, pero sí a la leche sin pasteurizar, como vectores de trasmisión de STEC. En este contexto, y dada la evidencia científica disponible actualmente en relación a E. coli productor de toxina Shiga, el SUH y el yogur, parecería que estamos ante la presencia de una correlación espuria, la asociación de dos hechos que no tienen relación causal entre sí, más que a un hecho científico del cual uno (el yogur) es el responsable del otro (SUH).

Some health professionals discourage yogurt because of the risk of Hemolytic Uremic Syndrome (HUS), a serious disease caused by strains of Shiga toxin-producing E. coli (STEC). These bacteria can pass from the intestine of cattle to meat or milk under inadequate working conditions in slaughterhouses or milking plants. Undercooked hamburgers the main is vector of disease and unpasteurized raw milk or dairy products made with it, are another risk factors. In the dairy industry, yoghurt is made from milk that undergoes a double heat treatment. There are no reports of the presence of STEC in industrial yogurts in the modern bibliography, and reviews and meta-analysis do not point to yogurt as a risk factor for STEC, but rather unpasteurized milk. In this context, and given the scientific evidence currently available regarding STEC, HUS and yogurt, it would seem that we are in the presence of a spurious correlation, the association between two facts that have no causal relationship between them, rather than a scientific fact for which one (yogurt) may be responsible for the other (HUS).

Characterization of recombinant Zea mays transglutaminase expressed in Pichia pastoris and its impact on full and non-fat yoghurts.

BACKGROUND: Transglutaminases catalyze post-translational modification of proteins by ε-(γ-glutamyl) links and covalent amide bonds. Research on properties and applications of plant transglutaminases is less developed than in animals and micro-organisms. In a previous study, optimized Zea mays transglutaminase was purified from recombinant Pichia pastoris strain. The main objective of the present study was to characterize this enzyme and assess its effect on the properties of yoghurt. RESULTS: The purified recombinant transglutaminase presented a Km of 3.98 µmol L(-1) and a Vmax of 2711 min(-1) by the fluorometric method. The enzyme was stable after incubation for 30 min below 50 °C and over a broad pH range of 5-8 at -20 °C for 12 h. The results showed that the crosslinking reaction catalyzed by this enzyme could effectively improve the properties of full and non-fat yoghurts. Also, the properties of non-fat yoghurt could be improved similar to the full-fat product by recombinant transglutaminase. CONCLUSION: The application of recombinant transglutaminase in yoghurt indicated that this enzyme could be used as a substitute for microbial transglutaminase in the production of yoghurt, thus providing experimental evidence for the future application of plant transglutaminases in the food industry.