There is a growing need for plant-based yogurts analogue that meet consumer demands in terms of texture and sensory qualities. Stabilizers are crucial in plant-based yogurt's physical properties which help develop a thicker and creamier texture, mimicking dairy yogurt. Thus, the study aims to evaluate the effect of pectin, corn starch, and locust bean gum (LBG) at different ratios on the physical, chemical, microbiological, and sensory properties of chickpea yogurts analogue (CYA). The concentration of stabilizer significantly influenced (p < 0.05) the proximate compositions, physicochemical and textural properties, and cell viability. CYA with 0.5% pectin showed the highest fat (4.75 ± 0.07) and protein content (2.39 ± 0.07), which were significantly different from other formulations. A significant increase (p < 0.05) was observed in yogurt viscosity with the addition of corn starch and LBG at 1.0%. Firmness and consistency were improved in samples supplemented with 1.0% corn starch. The sensory evaluation indicated that adding LBG at the ratio of 0.5% generated better preference among panelists in terms of the appearance, color, and texture aspects. Meanwhile, commercial CYA showed significantly higher overall acceptability (p < 0.05) than other samples. The stabilizer’s behavior significantly impacts the features of CYA, and which with 0.5% LBG received high consumer acceptance, indicating good potential for CYA to be on the same shelf with other commercial yogurts analogue in the market.

L. plantarum strains displayed different abilities to exhibit high survivability to acid (pH 3.0), bile salts (3%), enzyme (pepsin), and temperature (40 °C) and good antibiotic susceptibility. The isolates were further supplemented in traditional tapai pulut to study the immunomodulation properties of tapai pulut based on the splenic T- and B-cell populations. The mice groups were divided into group one (unfermented glutinous rice), group two (tapai pulut group), and group three (probiotic tapai pulut group). Group one showed consistent body weight gain, with the highest observed after four weeks. Group three exhibited the most significant reduction in the percentage of CD19+ B-cells. The CD3+ T-cells population of Group three increased significantly compared with the control mice, followed by Group two. The results suggest that traditional tapai pulut supplemented with L. plantarum has a high potential for supporting the immune system’s immunomodulatory effect.

The chemical, technological and allergy properties of goat’s milk are significantly affected by the level of α_s1-casein. Detection and quantification of α_s1-casein requires high-specificity methods to overcome high-sequence similarity between this protein and others in the casein family. Unavailability of antibodies with high affinity and specificity towards goat α_s1-casein hinders the development of immuno-based analytical methods such as enzyme-linked immunosorbent assay (ELISA) and biosensors. Here, we report the generation of polyclonal antibodies (or immunoglobulins, IgGs) raised towards goat α_s1-casein N- (Nter) and C-terminal (Cter) peptide sequences. The Nter and Cter peptides of goat α_s1-casein were immunized in rabbits for the generation of antisera, which were purified using protein G affinity chromatography. The binding affinity of the antisera and purified IgGs were tested and compared using indirect ELISA, where peptide-BSA conjugates and goat α_s1-casein were used as the coating antigens. The Nter antiserum displayed higher titer than Cter antiserum, at 1/64,000 and 1/32,000 dilutions, respectively. The purification step further yielded 0.5 mg/mL of purified IgGs from 3 mL of antisera. The purified Nter IgG showed a significantly (p < 0.05) higher binding affinity towards peptide-BSA and goat α_s1-casein, with lower K_d value at 5.063 × 10⁻³ μM compared to 9.046 × 10⁻³ μM for the Cter IgG. A cross-reactivity test showed that there was no binding in neither Nter nor Cter IgGs towards protein extracts from the milk of cow, buffalo, horse and camel. High-quality antibodies generated will allow further development of immuno-based analytical methods and future in vitro studies to be conducted on goat α_s1-casein.

We present a new approach for the detection of αs1-casein, a milk allergen, using tapered optical fiber sensor. The single-mode optical fiber of 125 μm diameter was tapered to produce waist diameter and length of 12 μm and 15 mm, respectively. The fiber sensor was functionalized using sodium hydroxide, (3-aminopropyl) triethoxysilane and glutaraldehyde to the tapered region. Anti-peptide polyclonal antibody from N-terminal sequence of αs1-casein was immobilized onto the tapered region, which subsequently bound to the introduced targeted αs1-casein. Measurement of transmission spectrum was performed within the wavelength range of 1500-1600 nm. Results showed that the shift of the wavelength in the fabricated sensor was linearly proportional to the increment of αs1-casein from 0.1 to 1.0 nM. The sensitivity of the sensor towards αs1-casein was measured at 1.139 nm/nM. Specificity was validated using bovine α-casein as a negative control with no significant wavelength shift. The sensor was tested using goat milk sample in three different dilutions to illustrate the applicability of the sensor in food matrices.