Antiproliferative, ACE-inhibitory and functional properties of protein hydrolysates from rohu (Labeo rohita) roe (egg) prepared by gastrointestinal proteases.

Previously, we have reported the chemical composition, molecular mass distribution and antioxidant activity of rohu roe protein hydrolysates. In the current study, antiproliferative, angiotensin-converting enzyme (ACE)-inhibitory activities and functional properties of protein hydrolysates from rohu (Labeo rohita) roe proteins, prepared by gastrointestinal proteases (pepsin and trypsin), were investigated. Antiproliferative activity was evaluated against human colon cancer cell line Caco-2. The results showed that the pepsin hydrolysate possessed dose dependent inhibitory effect on Caco-2 cell line. Pepsin and trypsin hydrolysates displayed ACE-inhibitory activity in vitro. The ACE-inhibitory activity of the hydrolysate generated by pepsin (47 ± 1.7 %, at 1 mg/ml) is higher than that obtained by trypsin (36 ± 3.2 %). Additionally, the undigested rohu roe proteins and its hydrolysates exhibited functional properties. Solubilities of the hydrolysates were above 81 ± 9.2 % at all pH values tested. Pepsin and trypsin hydrolysates showed good foaming capacity (45-211 %) and emulsification activity (4-29 m(2)/g). The foaming abilities and emulsifying activity index (EAI) were affected by pH. The results suggest that protein hydrolysates from rohu roe could be useful in food industry for various applications.

Antioxidant activity and functional properties of enzymatic protein hydrolysates from common carp (Cyprinus carpio) roe (egg).

Previously, we have reported the composition, molecular mass distribution and in vivo immunomodulatory effects of common carp roe protein hydrolysates. In the current study, antioxidative activity and functional properties of common carp (Cyprinus carpio) roe (egg) protein hydrolysates, prepared by pepsin, trypsin and Alcalase, were evaluated. The three hydrolysates showed excellent antioxidant activities in a dose dependent manner in various in vitro models such as 2,2 diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, 2,2'-azino-bis(3-ethylbenzthiazoline-6)-sulfonic acid (ABTS(+)) radical scavenging activity, ferric reducing antioxidant power (FRAP) and ferrous ion (Fe(2+)) chelating ability. Enzymatic hydrolysis significantly increased protein solubility of the hydrolysates to above 62 % over a wide pH range (2-12). Carp roe hydrolysates exhibited good foaming and emulsification properties. The results suggest that bioactive carp roe protein hydrolysates (CRPHs) with good functional properties could be useful in health food/nutraceutical/pharmaceutical industry for various applications.

Chemical composition and functional properties of mrigal (Cirrhinus mrigala) egg protein concentrates and their application in pasta.

Protein concentrates were prepared from underutilized mrigal (Cirrhinus mrigala) roe to produce value added by-products for food applications. Chemical composition and physicochemical properties of protein concentrates prepared from mrigal (Cirrhinus mrigala) roes were determined. The effects of pH and salt concentration on protein solubility were investigated. The protein content of the concentrates was found to be 75, and 91%, respectively for dehydrated and defatted powders. The maximum protein solubility was observed at pH 12, while minimum protein solubility was observed at pH 5, for both dehydrated and defatted protein concentrates. Salt concentration (0.1 to 1 M Nacl) significantly affected the solubility of protein concentrates. The mineral analysis revealed substantial amounts of iron and phosphorus. The emulsifying capacities of dehydrated and defatted protein concentrates were noted as 5.9, and 7.1 ml/g protein, respectively. SDS-PAGE analysis of fresh, dehydrated and defatted roe proteins has revealed the presence of major protein with a molecular weight (MW) of 97 kDa. Addition of defatted fish egg protein concentrate to pasta preparations had improved taste and texture. The results indicated that protein concentrates from underutilized mrigal fish egg may be useful for preparing protein rich food supplements.

Effects of pretreatments and salt concentration on rohu (Labeo rohita) roes for preparation of roe pickle.

In India, fish egg (roes) is the underutilized rich source of protein and essential fatty acids. An attempt was made to utilize the roes for the preparation of pickle product. Roes of rohu (Labeo rohita) were subjected to pretreatments such as pasteurization and blanching in varying molar concentrations of salt solutions to improve the texture and sensory quality. Losses in protein content and absorption of salt by roes were assessed in both pasteurized and blanched roes for processing them into roe pickle. The pasteurized roes were very soft coupled with high fishy odour. Roes blanched in 1M NaCl solution were found to be good in taste in terms of salt, minimum loss in protein content and reduced fishy odour. The blanched roes were used to prepare fish roe pickle. The pickle was analyzed for physico-chemical parameters, microbial and sensory quality during storage. The roe pickle packed in glass bottle was shelf-stable and scored good for sensory characteristics of flavour, texture, taste and overall acceptability during a storage period of 6 months at room temperature (28 ± 2°C).

Chemical composition and immunomodulatory effects of enzymatic protein hydrolysates from common carp (Cyprinus carpio) egg.

OBJECTIVES: The aim of this study was to prepare protein hydrolysates from underutilized common carp (Cyprinus carpio) egg and to investigate their immunomodulatory effects in vivo. METHODS: Common carp (Cyprinus carpio) egg (roe) was hydrolysed by pepsin, trypsin, and Alcalase. Chemical composition (proximate, amino acid, mineral and fatty acid compositions) and molecular mass distribution of the three hydrolysates were determined. The carp egg protein hydrolysates (CEPHs) were evaluated for their immunomodulatory effects in BALB/c mice. CEPHs (0.25, 0.5 and 1 g/kg body weight) were orally administered daily to female BALB/c mice (4-6 wk, 18-20 g) for a period of 45 d. After 45 d, mice were sacrificed and different tissues were collected for the immunologic investigations. RESULTS: The three hydrolysates contained high protein content (64%-73%) with all essential amino acids, and good proportion of ω-3 fatty acids, especially docosahexaenoic acid. Molecular mass analysis of hydrolysates confirmed the conversion of large-molecular-weight roe proteins into peptides of different sizes (5-90 kDa). The three hydrolysates significantly enhanced the proliferation of spleen lymphocytes. Pepsin hydrolysate (0.5 g/kg body weight) significantly increased the splenic natural killer cell cytotoxicity, mucosal immunity (secretory immunoglobulin A) in the gut and level of serum immunoglobulin A. Whereas Alcalase hydrolysate induced significant increases in the percentages of CD4+ and CD8+ cells in spleen. CONCLUSIONS: The results demonstrate that CEPHs are able to improve the immune system and further reveal that different CEPHs may exert differential influences on the immune function. These results indicate that CEPHs could be useful for several applications in the health food, pharmaceutical, and nutraceutical industries.

Fish protein hydrolysates: proximate composition, amino acid composition, antioxidant activities and applications: a review.

The fish processing industry produces more than 60% by-products as waste, which includes skin, head, viscera, trimmings, liver, frames, bones, and roes. These by-product wastes contain good amount of protein rich material that are normally processed into low market-value products, such as animal feed, fish meal and fertilizer. In view of utilizing these fish industry wastes, and for increasing the value to several underutilised fish species, protein hydrolysates from fish proteins are being prepared by several researchers all over the world. Fish protein hydrolysates are breakdown products of enzymatic conversion of fish proteins into smaller peptides, which normally contain 2-20 amino acids. In recent years, fish protein hydrolysates have attracted much attention of food biotechnologists due to the availability of large quantities of raw material for the process, and presence of high protein content with good amino acid balance and bioactive peptides (antioxidant, antihypertensive, immunomodulatory and antimicrobial peptides).

Studies on lipid profiles and fatty acid composition of roe from rohu (Labeo rohita) and murrel (Channa striatus).

The lipid profiles and fatty acid composition of roes from two common fresh water fish viz., rohu (Labeo rohita) and murrel (Channa striatus) have been studied. The dehydrated fish egg was ground to fine powder and extracted with chloroform/methanol (2:1, v/v) to recover the total lipid in 20.2 and 22.7% on dry weight basis. The fat free meal was found to contain 70 and 58% protein in rohu and murrel, respectively. The total lipids were separated into neutral lipids, glycolipids and phospholipids using silica gel column chromatography and found to be 43.8, 72.9% neutral lipids; 12.7, 9.4% glycolipids and 43.5, 17.7% phospholipids in rohu and murrel roes, respectively. The fatty acid compositions of all lipid classes were analysed by GC and GC-MS. Among the saturated fatty acids, hexadecanoic acid (16:0) was found to be 30.2 and 30.4% respectively in rohu and murrel total lipid. n-3 Fatty acids namely eicosapentaenoic acid (20:5, EPA) was observed to an extent of 1.5 and 0.6% and docosahexaenoic acid (22:6, DHA) to an extent of 11.8 and 6.1% respectively in rohu and murrel total lipids. Stearic acid (18:0) was also seen at 12.2 and 6% respectively in rohu and murrel lipids. The fatty acid composition was found to be almost similar in all the lipid classes. The study indicated that rohu and murrel fish egg lipids are good sources for polyunsaturated n-3 fatty acids.