Freshly squeezed kasturi lime fruit juice was sonicated (for 0, 30 and 60min at 20°C, 25kHz frequency) to evaluate its impact on selected physico-chemical and antioxidant properties, such as pH, °Brix, titratable acidity, Hunter color values (L(∗), a(∗), b(∗)), ascorbic acid, DPPH radical scavenging activity, total phenolics, antioxidant capacity, flavonoids and flavonols. Additionally, the effect of sonication treatments on the microbial load (TPC, yeast and mold) were also evaluated. Sonication of juice samples for 60min showed enhancement in most of the bioactive compounds compared to samples treated for 30min and control samples (untreated). Significant reductions in the microbial load corresponding to sonication time were also recorded. Results of the present study indicate that sonication may be employed as a suitable technique for kasturi lime juice processing, where antioxidant and other bioactive compound retention or enhancement is desired, along with the achievement of safety and quality standards.
The growth and survival of Salmonella typhimurium in goat milk samples at different shifting temperatures were evaluated. The growth of S. typhimurium at lower temperatures (5°C, 10°C, and 15°C) exhibited bacteriostatic effects in milk, whereas at ambient temperature (25°C) and at 45°C, this pathogen luxuriantly grew throughout the 12-h stationary phase. At 50°C this pathogen was found to be thermotolerant and could still thrive in the milk. Overall, shifting temperatures from 37°C to 55°C and 60°C clearly indicated S. typhimurium to have reached complete elimination. The results demonstrated that the adaptation and survival of this pathogen directly depend on temperature stress. It is expected that the results will be useful to dairy industries for implementation of good manufacturing practices with a better hazard analysis critical control point approach to predict the microbial risk assessment and also benefit the consumers.
The present study was conducted to examine the effects of sonication treatments (time intervals of 0, 15, 30, 45 and 60 min.) on phenolics and other antioxidant compounds in starfruits extracted in methanol and water. Overall, methanolic extracts exhibited significantly higher extractability, percentage inhibition of DPPH radicals, ferric reducing antioxidant property (FRAP) value, antioxidant capacity, flavonoids, total phenolics and tannins (p min) and aqueous extracts. Methanolic extract obtained after 30 min of sonication proved to be the best treatment with regard to various parameters evaluated. Results of the present study clearly indicated sonication treatments to be effective in enhancing the antioxidant compounds in starfruit extracts and could be further explored for commercial purposes to benefit the consumers.