Gelatin is a biopolymer that can be generated from partially hydrolysis of collagen tissue. Extraction of gelatin consists of pretreatment and thermal extraction steps. Pretreatment process used sodium hydroxide to remove non collagen protein in matrix sample, sulfuric acid to demineralize, and citric acid to hydrolyse. The aim of this research was to study the effect of variation in concentrations of citric acid used in hydrolysis process on the gel strength and protein profile of gelatin products extracted from broiler chicken skin.  The variation of the concentration citric acid used was 0.7 % (GA); 1.5% (GB); and 3.0% b/v (GC) respectively. The gel strength was measured using CT3 Texture Analyzer and protein profile of gelatin product was analyzed by SDS-PAGE method. The result showed that variation in concentration of citric acid used in the pretreatment process affected the gel strength and protein profile of gelatin product. Increasing the concentration of citric acid used in pretreatment process decreased the gel strength and molecular weight of gelatin product. Gel strength of each gelatin product was 265.81 g bloom for GA ; 196.05 g bloom for GB (1.5%), and 35.32 g bloom for GC (3.0 %) respectively. The electropherogram of both GA (0.7%) and GB (1.5%) revealed similar pattern of protein bands but the thickness of each bands was different.  On the other hands, GC (3.0%) did not show any protein bands on the eletropherogram. The best gelatin product obtained in this experiment was found by using 0.7 % b/v citric acid (GA) in the pretreatment process. The gelatin product (GA) had characteristics as follows: yield 15.73%; moisture 7.30%; ash 0.51%; protein content 97.95%; fat content 0.62%; gel strength 265. 81 g bloom and thicker protein bands than others.

During the germination process, seeds can release various types of peptides due to the degradation of storage proteins. Some of these peptides can have biological activity (bioactive peptides). The objective of this study was to determine the ACE inhibitory activity of germinated pigeon pea peptide extract at various germination times and to carry out the fractionation to the extract to get the most active peptide fraction. The results showed that the highest activity of peptide extract was found on the 4th-day germination of pigeon pea with an IC50 value of 63.46 μg/mL. The peptide extract was further fractionated by centrifugal ultrafiltration method and it was found that the peptide fraction < 3 kDa had the highest ACE inhibitory activity with an IC50 value of 57.79 μg/mL. The result of identification with the LCMS method to the fraction was able to detect 4 types of the peptide with a molecular weight of 230.304, 294.303, 441.436, and 570.591 Da. These results suggested that the peptide fraction of germinated pigeon pea has the potency as an ACE inhibitory nutraceutical.

Protein hydrolysate contains a mixture of various lengths of short peptides chain and free amino acids that may excert biological activities. This research aims to screen potential antioxidant and antibacterial activities of protein hydrolysate produced from three kinds of germinated beans i.e. lablab bean (Lablab purpureus), pigeon pea (Cajanus cajan (L.) Millsp) and kidney bean (Phaseolus vulgaris) through enzymatic hydrolysis process. The steps of research included germination process of the beans prior to total protein isolation, enzymatic hydrolysis of total protein isolates using pancreatin enzyme, evaluation of in vitro antioxidant activity of the hydrolysates protein using DPPH (1,1-diphenyl-2-picryl hydrazyl) method, and antibaterial activity testing towards Eschericia coli and Staphyllococcus aureus bacteria. The results revealed that pancreatine enzyme was able to hydrolyse germinated protein of lablab bean, pigeon pea and kidney bean at the experiment condition applied with degree of hydrolysis 34.12%, 27.44%, and 30,93% respectively. It was also found that protein hydrolysates of lablab bean, pigeon pea, and kidney bean demonstrated antioxidant activity which percentage radical DPPH scavenging activity of 84.02%, 68.97% and 67.89 %. On the other hand, all of those protein hydrolysates did not show any antibacterial activity towards Eschericia coli and Staphyllococcus aureus bacteria.

Germination can activate the degradation of storage protein in legumes releasing peptides and free amino acids for seed growth. These compounds have many benefits in many fields, especially in food and health. This study aimed to determine the effect of solvent type and germination time on the level of free amino acids (FAA) and the level of peptides (MW < 10 kDa) of germinated pigeon pea extract. The extraction of free amino acids and the dissolved protein from germinated pigeon pea flour was carried out using two kinds of solvents, namely water, and 0.1 N HCl. The variation of germination times of pigeon pea seeds was carried out at 12, 24, 36, 48, 60, 72, 84, and 96 hours. The level of FAA was determined spectrophotometrically using the ninhydrin method after the deproteination step, while the level of peptides was determined spectrophotometrically using the biuret method. The results showed that using 0.1 N HCl as a solvent produced a higher level of FAA and peptides in the extract than using water. The increase of germination time can increase the level of FAA with the peak achieved in 36 hours. The increase of germination time can increase the level of peptides with the peak of peptides level achieved on 84 hours of germination. These results showed that seed germination is a potential method for producing free amino acids and peptides which accumulate at a specific time

Telah dilakukan penelitian tentang Skrining Potensi Beberapa Jenis Biji Polong-polongan (Famili Fabaceae) dan Biji Labu-labuan (Famili Cucurbitaceae) Sebagai Kuagulan Alami Pengganti Tawas. Potensi biji-bijian ditentukan dengan metode turbidimetri dengan menghitung persentase penurunan turbiditas dari masing-masing biji-biji tersebut yang diujikan pada sampel air.             Hasil Penelitian menunjukkan bahwa serbuk biji asam jawa dari suku polong-polongan terbukti mampu berperan sebagai kuagulan alami, sedangkan biji bari suku labu-labuan kurang potensial menurunkan kekeruhan air. Persen penurunan kekeruhan dengan menggunakan kuagulan biji dari suku polong-polongan (lamtoro, merak, asam jawa) berturut-turut 32,35%, 39,99%, 62,75% dan biji dari suku labu-labuan (labu kuning, melon, semangka) berturut-turut  47,50%, 44,71%, 51,81%.