RESUMEN
The survivability of encapsulated and nonencapsulated probiotics consisting of Lactobacillus acidophilus and Lacticaseibacillus casei and the nutritional, physicochemical, and sensorial features of cottage cheese were investigated under refrigeration storage at 4 °C for 28 days. Microbeads of L. acidophilus and L. casei were developed using 2% sodium alginate, 1.5% sodium alginate and 0.5% carrageenan, and 1% sodium alginate and 1% carrageenan using an encapsulation technique to assess the probiotic viability in cottage cheese under different gastrointestinal conditions (SGF (simulated gastric juice), SIF (simulated intestinal fluid)), and bile salt) and storage conditions. Scanning electron microscopy (SEM) elucidated the stable structure of microbeads, Fourier transform infrared spectroscopy (FTIR) confirmed the presence probiotics in the microcapsules, and X-ray diffraction (XRD) demonstrated the amorphous state of microbeads. Furthermore, the highest encapsulation efficiency was observed for alginate 1% and carrageenan 1% microbeads (T3), i.e., 95%. Likewise, viability was recorded in T3 against SGF, SIF, and bile salt solution, i.e., 8.5, 8.8, and 8.9 log CFU/g at 80 min of exposure, compared to the control. The results of pH showed a significant (p < 0.05) decline that ultimately increased the titratable acidity. Nutritional analysis of cottage cheese revealed the highest levels of ash, protein, and total solids in T3, exhibiting mean values of 3.2, 22, and 43.2 g/100 g, respectively, after 28 days of storage. The sensory evaluation of cottage cheese demonstrated better color, flavor, and textural attributes in T3. Conclusively, synergistic addition of L. acidophilus and L. casei encapsulated with alginate-carrageenan gums was found to be more effective in improving the viability of probiotics in cottage cheese than noncapsulated cells while carrying better magnitudes of ash and protein, lower acidity, and pleasant taste.
RESUMEN
Guava is an important climacteric fruits in terms of taste and aroma, which contains various vital nutrients such as minerals, carotenoids, ascorbic acid, and polyphenols. At ambient conditions, it exhibits a short shelf life, which makes it difficult for marketing and subsequent storage. Therefore, it is necessary to develop procedures to extend its shelf life and conserve quality. For this purpose, an aloe vera (AV) gel coating was assessed for its potential to enhance the shelf life of guava fruits. Guava fruits coated with AV gels (0, 20, 40, 60 and 80%, v/v) were evaluated for postharvest shelf life extension, changes in quality attributes, anti-oxidative activities, and flavonoid content when stored at ambient conditions (23 ± 2 °C and 70-75% relative humidity) for 12 days. The AV gel-treated fruits showed reduced increments in total sugar, malondialdehyde, and total carotene contents compared to untreated controls. AV gel-treated fruits exhibited higher contents of ascorbic acid, flavonoids (quercetin and rutin), and total phenolics in comparison to control fruits. Moreover, AV gel-treated fruits displayed greater activities of superoxide dismutase, catalase, and ascorbate peroxidase, along with higher antioxidant capacity and higher levels of total soluble solids, than untreated fruits. These results demonstrate that AV gel coating, especially at high concentrations, can be considered an eco-friendly and non-chemical substitute treatment for maintaining the postharvest quality of guava fruit.