N. Bhaskar

In vitro antioxidant activity of liquor from fermented shrimp biowaste.

Shrimp waste was fermented using lactic culture and the separated fermented liquor was lyophilized. In vitro antioxidant activities of the lyophilized powder were evaluated with respect scavenging of different radicals and quenching of generated singlet oxygen. The sample showed strong radical scavenging and singlet oxygen quenching in a dose dependent manner (p<0.001). The sample exhibited 40% scavenging of DPPH radical at 1.0mg/ml concentration while the ABTS radical scavenging was 95% even at 0.5mg/ml concentrations. Hydroxyl radical scavenging activity as measured by chemiluminescence technique showed 80% scavenging and peroxyl radical scavenging was 65% at 1.0mg/ml concentration. The singlet oxygen quenching ability of the powder was 68.3% at 1.0mg/ml concentration. The sample was found to contain low molecular weight proteins. The formation of peptides and amino acids during hydrolysis of shrimp waste protein during fermentation is expected to be responsible for the antioxidant activity. In addition as the product also contains carotenoids, it can be used as an ingredient in aquaculture feed formulations for beneficial effects.

Effect of Acid Ensiling on the Stability of Visceral Waste Proteases of Indian Major Carp Labeo rohita

ABSTRACT The effect of acid ensiling on the stability of different classes of proteases present in the visceral wastes of a major freshwater carp is presented. The changes in moisture, fat and ash content were not significant (P ≥ 0.05) during the storage period of 4 weeks at ambient temperature of 27 ± 2°C. Fresh visceral waste of the freshwater major carp Labeo rohita had considerable protease activity and buffer extractable proteins (2.7% w/w). There was a significant reduction in buffer extractable proteins (BEP) immediately after acidification (P ≤ 0.05), which later increased in the first two weeks before decreasing further during storage. Marked decreases (P ≤ 0.05) in specific activity (Umg−1 protein) of acidic, neutral and alkaline proteases were observed during storage. The stability of proteases was negatively affected by acid ensiling, even with the use of weak acids like propionic and formic acid.

Influence of Freeze-Dried Shrimp Meat in Pasta Processing Qualities of Indian T. durum Wheat

The present study aims to understand the influence of freeze-dried shrimp (Penaeus monodon) meat (SM) at different levels (2.5, 5, and 10%; w/w) in pasta processing. The rheological characteristics studies of SM-wheat flour blends indicated that dough stability increased with the increased addition of SM in the blends, whereas farinograph water absorption and amylograph peak viscosity decreased. Cooking loss increased with increasing levels of SM in the pasta (7.3% in 10% SM pasta; 6.7% in control pasta). However, all pasta samples were in the acceptable range. Color analysis of the pasta sample indicated that the L values increased with increasing levels of pasta. The instrumental texture of cooked pasta indicated that 10% SM pasta was significantly (p < 0.05) firmer (1.84 N) than that of the control (1.35 N). Microstructure studies revealed that incorporation of SM in the pasta had a better protein network. Pasta with 5% SM had the highest mean score for all sensory attributes, with increased levels of essential nutrients, fatty acids such as eicosapentaenoic acid and docosahexaenoic acid, and amino acids such as lysine.

Fermentative properties of proteolytic pediococcus strains isolated from salt fermented fish hydrolysate prepared using freshwater Fish Rohu (Labeo Rohita)

ABSTRACT Salt fermented fish hydrolysate (SFFH) was prepared from freshwater fish Rohu (Labeo rohita), an Indian major carp, using salt at room temperature for 50 days. Total lactic acid bacteria (LAB) counts of SFFH prepared using 20% and 30% NaCl (w/w) were found to be in the range of 5.83–7.25 log cfu/ml and 3.93–5.46 log cfu/ml, respectively, whereas the log cfu/ml values for the halotolerant LAB counts varied from 2.09 to 7.17 and 2.02 to 4.77, respectively. Out of 96 isolates from SFFH, 21 isolates were screened based on their pH reducing ability, total titratable acidity, and proteolytic properties. Morphological, biochemical, and molecular characterization of four selected LAB strains were carried out. The isolates FSAP3-3 (Pediococcus pentosaceus), FSBP4-40 (Pediococcus pentosaceus), FSBP16-40 (Pediococcus pentosaceus), and FSBP28-50 (Pediococcus acidilactici) showed both halotolerant and proteolytic properties. The identified LAB isolates showed antagonistic properties against several human pathogens and exhibited sensitivity toward a broad spectrum of antibiotics. All the identified LAB isolates showed excellent proteolytic activity and phosphohydrolase activity. These halotolerant LAB isolates that had both proteolytic properties and acidifying ability have the potential for application in an acceleration of fermentation to produce salted fish products (i.e., fish sauce, fish paste, fish mince, etc.).