Physicochemical properties and angiotensin-I converting enzyme inhibitory activity of lipid-free ribbon fish (Lepturacanthus savala) protein hydrolysate.

The study aims at removal of lipid from ribbon fish protein hydrolysate (FPH) to enhance the protein content and analyse its physicochemical and bioactive properties. Ribbon fish protein hydrolysate was prepared using commercially available papain enzyme (1.5% w/v for 4 h). The resulting supernatant was further treated with lipase (0.5-2.0% w/v for 1-5 h). The treatment used in this study reduced ~ 98% of lipids depending on the enzyme concentration, temperature, pH, and duration of the treatment. Lipase treatment for 2 h increased the protein content from 62.87 to 94.11%. FPH after lipase treatment showed 1.21 folds increase in angiotensin-converting enzyme-I (ACE-I) inhibitory activity and 1.7 folds increase in standard amino acids composition (32.193 to 61.493 g/100 g). The physicochemical properties of FPH samples were analyzed by solubility, hygroscopicity, color, FT-IR, SEM, SDS-PAGE, and Zeta Potential. Use of lipase enzyme for separating the lipid content from protein hydrolysate without conferring any undesirable adverse effects on the physicochemical properties of protein hydrolysate. Lipid-free protein hydrolysates can be of commercial importance for their enhanced ACE-I inhibitory activity, replacing the side effect causing synthetic drugs for hypertension, and can have potential applications in developing functional food formulations. Supplementary Information: The online version contains supplementary material available at 10.1007/s13197-022-05620-z.

WITHDRAWN:Effect of Sodium Chloride Replacement on the Sensory and Physico-Chemical Properties of Restructured Chicken Jerky.

Replacement of sodium chloride (NaCl) with potassium chloride (KCl) and potassium lactate (KLact) in restructured chicken jerky was studied. The experiment was conducted considering three levels of each NaCl (1%, 1.5%, 2%), KCl (0%, 0.5%, 1%) and KLact (0%, 0.5%, 1%) resulting in six treatments with a total salt content of 2% in the product. Physico-chemical and sensory properties of the jerky containing salt replacers were examined and the most suitable NaCl replacement was to be identified. The jerky samples had moisture content below 25%, more than 60% protein and about 5-6% fat. All samples attained a water activity level below 0.8 after 5 hours of drying. Reduction of NaCl in jerky led to increased shrinkage and shear force values. Significant difference was also observed in the hunter color values especially in the case of L* values which increased as the NaCl content in the samples decreased. Scanning electron microscopy images showed that replacing NaCl reduced the structural density and compactness in jerky. Sensory panelists preferred treatments with only KCl. According to principal component analysis carried out and from sensory point of view, 50% replacement of NaCl with KCl was found to be most suitable strategy for developing low sodium jerky without compromising the product quality. (Key words: Restructured jerky, salt replacement, Sensory analysis, JAR profile, Microstructure, Dried meat).

Effects of amino acid derivatives on physical, mental, and physiological activities.

Nutritional ergogenic aids have been in use for a long time to enhance exercise and sports performance. Dietary components that exhibit ergogenic activity are numerous and their consumption is common and popular among athletes. They often come under scrutiny by legal authorities for their claimed benefits and safety concerns. Amino acid derivatives are propagated as being effective aids to enhance physical and mental performance in many ways, even though studies have pointed out that individuals who are deficient are more likely to benefit from dietary supplementation of amino acid derivatives than normal humans. In this review, some of the most common and widely used amino acids derivatives in sports and athletics namely creatine, tyrosine, carnitine, HMB, and taurine have been discussed for their effects on exercise performance, mental activity as well as body strength and composition. Creatine, carnitine, HMB, and taurine are reported to delay the onset of fatigue, improve exercise performance, and body strength. HMB helps in increasing fat-free mass and reduce exercise induced muscle injury. Taurine has been found to reduce oxidative stress during exercise and also act as an antihypertensive agent. Although, studies have not been able to find any favorable effect of tyrosine administration on exercise performance, it has been proved to be very effective in fighting stress, improving mood and cognitive performance particularly in sleep-deprived subjects. While available data from published studies and findings are equivocal about the efficacy of creatine, tyrosine, and HMB, more comprehensive researches on carnitine and taurine are necessary to provide evidence for the theoretical basis of their ergogenic role in nutritional modification and supplementation.