Effects of Commercial Polysaccharides Stabilizers with Different Charges on Textural, Rheological, and Microstructural Characteristics of Set Yoghurts

Formulations and assessments of structure, physical properties, and sensory attributes of soy yogurts: Effect of carboxymethyl cellulose content and degree of substitution

Soy yogurts present challenges, including absence of tender and slipperiness mouthfeel, and poor stability. This study aimed to investigate the impacts of carboxymethyl cellulose (CMC) with degrees of substitution of 0.7 (CMC0.7) and 1.2 (CMC1.2) at concentrations ranging from 0 % to 1.1 % on the stability, microstructure, rheology, tribology, and mouthfeel of soy yogurts. As the CMC concentration increased from 0 % to 0.3 %, soy yogurts displayed a coarser microstructure, decreased stability, and increased gel strength. As the concentration of CMC further increased from 0.5 % to 1.1 %, soy yogurts exhibited trends of a smoother microstructure, increased stability, and softer gel strength. Notably, soy yogurts with CMC0.7 demonstrated a superior water holding capacity (WHC) than soy yogurts with CMC1.2. Tribological measurements indicated that soy yogurts with CMC0.7 at a 0.7 % concentration had the lowest coefficient of friction (COF) value among most sliding speeds, showing a 23 % reduction compared to soy yogurts without CMC at a sliding speed of 10 mm/s. Moreover, sensory evaluation showed that soy yogurts with CMC0.7 at a 0.7 % concentration had the highest total score in mouthfeel evaluation. Therefore, the addition of CMC0.7 within the concentration range of 0.5 % to 1.1 % may produce stable and delicate yogurts.

Physical and Chemical Properties, Flavor and Organoleptic Characteristics of a Walnut and Purple Rice Fermented Plant Drink

In recent years, green and healthy foods have attracted much attention. Plant-based foods have become an alternative to animal-derived foods. In this study, we used walnut and purple rice as the primary raw materials to produce a fermented plant drink. The process included boiling, mixing, grinding, inoculation, fermentation, and sterilization. We then analyzed the similarities and differences between the resulting walnut and purple rice fermented plant drink and an unfermented walnut and purple rice plant drink, as well as dairy-based yoghurt, in terms of physical chemistry, flavor, and sensory characteristics. We also examined the similarities and differences between the walnut and purple rice fermented plant drink and room-temperature yoghurt. The study results revealed that the walnut and purple rice fermented plant drink exhibited greater viscosity than the walnut and purple rice unfermented plant drink and room-temperature yoghurt. Additionally, the former displayed enhanced stability and recovery ability. Notably, distinguishable differences were observed between the three samples in terms of the presence of unknown volatiles and the umami signal, as indicated by electronic nose/tongue and GC-IMS analyses. The umami flavor of the walnut and purple rice fermented plant drink surpasses that of room-temperature yoghurt, while its taste is less salty than that of the walnut and purple rice plant drink. Despite possessing a weaker aroma than dairy-based yogurt, it is more potent than the walnut and purple rice plant drink. Additionally, its relative abundance of olefins, ketones, and alcohols enhances its unique flavor profile, surpassing both other options. Based on sensory analysis, it can be deduced that walnut and purple rice fermented plant drink has the highest overall acceptance rate.

Sodium alginate/carboxymethyl cellulose films embedded with liposomes encapsulated green tea extract: characterization, controlled release, application

To maintain the freshness of the fruit during storage, sodium alginate/carboxymethyl cellulose films embedded with pH-senstive liposomes encapsulated green tea extract were developed (SA/CMC/TP-Lip). An orthogonal design was used to optimise the preparation of TP-Lip and SA/CMC/TP-Lip was prepared through response surface. The stability of TP-Lip structure was measured. The morphology of SA/CMC/TP-Lip was characterised by SEM, and the mechanical properties and oxidation resistance of films were measured. Special attention was paid to the pH sensitivity of TP-Lip and the improvement of film properties. The zeta potential and encapsulation rate of TP-Lip were -45.85 ± 2.13 mV and 61.45 ± 0.23%. The average release rate of TP encapsulated into TP-Lip at pH 3 was 41.08%, an increase of 23.07% over pH 6 during 12 h. SEM and FTIR showed that TP-Lip was structurally stable and had good compatibility with SA/CMC. Tensile strength was increased by 30.55% and DPPH radical scavenging capacity was increased by 7.16% with the addition of TP-Lip. SA/CMC/TP-Lip is applied to blueberries to reduce their weight loss and improve the loss of freshness of blueberries during storage. Thus, SA/CMC/TP-Lip could provide a new way to extend active packaging materials and maintain fruit freshness during storage.

Application of natural and modified additives in yogurt formulation: types, production, and rheological and nutraceutical benefits

Yogurt, a popular fermented dairy product, is of different types and known for its nutritional and nutraceutical benefits. However, incorporating additives into yogurt has been adopted to improve its functionality and nutraceutical properties. Additives incorporated in yogurt may be natural or modified. The incorporation of diverse natural additives in yogurt formulation, such as moringa, date palm, grape seeds and argel leaf extracts, cornelian cherry paste, mulberry fruit and leaf powder, lentil flour, different types of fibers, lemongrass and spearmint essential oils, and honey, has been reported. Similarly, modified additives, such as β-glucan, pectin, inulin, sodium alginate, and gelatin, are also added to enhance the physicochemical, textural, sensory, and rheological properties of yogurt. Although additives are traditionally added for their technological impact on the yogurt, studies have shown that they influence the nutritional and nutraceutical properties of yogurt, when added. Hence, yogurts enriched with functional additives, especially natural additives, have been reported to possess an improved nutritional quality and impart several health benefits to consumers. These benefits include reducing the risk of cardiovascular disease, cancer, osteoporosis, oxidative stress, and hyperglycemia. This current review highlights the common types of yogurt, the production process, and the rheological and nutraceutical benefits of incorporating natural and modified additives into yogurt.

Purification of Galacto-oligosaccharide (GOS) by fermentation with Kluyveromyces lactis and Interaction between GOS and casein under simulated acidic fermentation conditions

In the enzymatic synthesis of galacto-oligosaccharide (GOS), the primary by-products include glucose, galactose and unreacted lactose. This This study was aimed to provide a method to to purify GOS by yeat fermentation and explore the interaction between GOS and CAS with a view for expanding the prospects of GOS application in the food industry. The crude GOS(25.70 g/L) was purified in this study using the fermentation method with Kluyveromyces lactis CICC 1773. Optimal conditions for purification with the yeast were 75 g/L of the yeast inoculation rate and 50 g/L of the initial crude GOS concentration for 12 h of incubation. After removing ethanol produced by yeast by low-temperature distillation, GOS content could reach 90.17%. A study of the interaction between GOS and casein (CAS) in a simulated acidic fermentation system by D-(+)-gluconic acid δ-lactone (GDL) showed that the GOS/CAS complexes with higher GOS concentrations, e.g., 4% and 6% (w/v), was more viscoelastic with higher water-holding capacity, but decreased hardness, elasticity, and cohesiveness at 6% (w/v) of GOS. The addition of GOS to CAS suspension significantly caused (p<0.05) decreased particle sizes of the formed GOS/CAS complexes, and the suspension system became more stable. FT-IR spectra confirmed the existence of different forms of molecular interactions between CAS and GOS, e.g., hydrogen bonding and hydrophobic interaction, and the change of secondary structure after CAS binding to GOS.

The physical and structural properties of acid-Ca2+ induced casein-alginate/Ca2+ double network gels

The design of protein or polysaccharide interpenetrating network gels according to their physicochemical properties is required to obtain the desired properties of hydrogels. In this study, a method was proposed to prepare casein-calcium alginate (CN-Alg/Ca²⁺) interpenetrating double-network gels by the release of calcium from a calcium retarder during acidification to form calcium-alginate (Alg/Ca²⁺) gel and casein (CN) acid gel. Compared with the casein-sodium alginate (CN-Alg) composite gel, the CN-Alg/Ca²⁺ dual gel network with an interpenetrating network gel structure has better water-holding capacity (WHC) and hardness. The rheology and microstructure results showed that the dual-network gels of CN and Alg/Ca²⁺ induced by gluconic acid-δ-sodium (GDL) and calcium ions were the network structure of the Alg/Ca²⁺ gel, which was the "first network", and the CN gel, which was the "second network". It was proven that the microstructure, texture characteristics, and WHC of the double-network gels could be regulated by changing the concentration of Alg in the double-network gels and that the 0.3 % CN-Alg/Ca²⁺ double gels showed the highest WHC and firmness values. The aim of this study was to provide useful information for the preparation of polysaccharide-protein mixed gels in the food industry or other fields.

Comparative analysis of exopolysaccharide-producing Lactiplantibacillus plantarum with ropy and non-ropy phenotypes on the gel properties and protein conformation of fermented milk

In this study, we evaluated the impact of Lactiplantibacillus plantarum (L. plantarum) with ropy and non-ropy phenotypes on gel structure and protein conformation of fermented milk. Ropy L. plantarum (T1 & CL80) secreted EPS with high molecular weight (1.41 × 10⁶, 1.19 × 10⁶ Da) and intrinsic viscosity (486.46, 316.32 mL/g), effectively enhances fermented milk viscosity and water holding capacity (WHC) (65.4%, 84.6%) by forming a dense gel structure. Non-ropy L. plantarum (CSK & S-1A) fermented milk gel's high surface hydrophobicity and free sulfhydryl content caused high hardness and low WHC. Raman spectroscopy combined with circular dichroism analysis showed that high levels of α-helix (29.32-30.31%) and random roil (23.06-25.36%) protein structures are the intrinsic factors that contribute to the difference among fermented milk gels of ropy and non-ropy strains. This study provides a basis for understanding the structural variability of fermented milk gels using ropy or non-ropy lactic acid bacteria.

Physicochemical, Textural, and Sensorial Properties of Soy Yogurt as Affected by Addition of Low Acyl Gellan Gum

Soy yogurt is plant-based dairy of great nutritional interest that is widely accepted in developing countries as a milk alternative. Poor stability has been an urgent problem to solve of soy yogurt products over past several years. The present study aimed to construct multiple network composite gel by adding low acyl gellan gum (LAG) to improve the stability. The effect of addition of LAG on property of soy yogurt was investigated by determining water holding capacity, texture, rheology, particle size, and zeta potential. The results showed that water holding capacity was significantly higher than control. The soy yogurt with 0.1% LAG had a stable gel network with much gel strength and viscosity, and strengthened interaction between complex gel. The addition of LAG increased the particle size and decreased zeta potential. Furthermore, sensory properties were acceptable. Therefore, during industrial production, LAG could act as an appropriate stabilizer to inhibit poor body and bring more desirable sensory characteristics of soy yogurt.