Supatra Karnjanapratum

Chemical compositions and nutritional value of Asian hard clam (Meretrix lusoria) from the coast of Andaman Sea.

Chemical compositions and nutritive value of the edible portions including foot, mantle and viscera of Asian hard clam (Meretrix lusoria) harvested from the coast of Andaman Sea were determined. Proximate compositions varied with portions tested. Edible portions had moisture (76.23-84.22%) and protein (9.09-12.75%) as the major components. Carbohydrate (0.32-7.89%), fat (1.58-6.58%) and ash (1.23-2.58%) were also found at various levels, dependent upon portions. Myofibrillar proteins were observed as the major fraction in foot (40.54%) and mantle (31.65%), whilst non-protein nitrogen constituents were dominant in the viscera (36.85%). All portions contained a large amount of essential amino acids (167.66-187.63 mg/g sample), in which leucine (30.91-36.96 mg/g sample) and lysine (35.24-36.03 mg/g sample) were predominant. They were rich in polyunsaturated fatty acids (46.84-49.18% of total fatty acid) with high level of DHA (13.33-16.47 % of total fatty acids) and EPA (4.75-7.11% of total fatty acids). Cholesterol of 0.07-0.21% wet weight was detected. All portions were also rich in macro- (Na, K, Ca and Mg) and micro- (Fe, Zn, Cu and Cr) minerals. Therefore, Asian hard clam is an excellent source of several nutrients, which could be beneficial for the health of the consumers.

Antioxidant, immunomodulatory and antiproliferative effects of gelatin hydrolysate from unicorn leatherjacket skin

BACKGROUND The in vitro cellular bioactivities including, antioxidant, immunomodulatory and antiproliferative effects of a gelatin hydrolysate (GH) prepared from unicorn leatherjacket skin, using partially purified glycyl endopeptidase, were investigated in order to optimize the use of fish skin waste products as functional food ingredients. RESULTS GH under the tested concentrations (750-1500 µg mL(-1) ) protected against H2 O2 -induced DNA damage in U937 cells. GH also protected against the H2 O2 -induced reduction in cellular antioxidant enzyme activities, superoxide dismutase and catalase, in HepG2 cells. GH demonstrated immunomodulatory potential by reducing pro-inflammatory cytokine (interleukin-6 (IL-6) and IL-1β) production and nitric oxide production in lipopolysaccharide-stimulated RAW 264.7 macrophage cells. Cell proliferation in human colon cancer (Caco-2) cells was significantly reduced in a dose-dependent manner following incubation with GH. CONCLUSION These results indicate that GH has several bioactivities which support its potential as a promising functional food ingredient with various health benefits.

Glycyl endopeptidase from papaya latex: partial purification and use for production of fish gelatin hydrolysate.

An aqueous two-phase system (ATPS) in combination with ammonium sulphate ((NH4)2SO4) precipitation was applied to fractionate glycyl endopeptidase from the papaya latex of Red Lady and Khack Dum cultivars. ATPS containing polyethylene glycol (PEG 2000 and 6000) and salts ((NH4)2SO4 and MgSO4) at different concentrations were used. Glycyl endopeptidase with high purification fold (PF) and yield was found in the salt-rich bottom phase of ATPS with 10%PEG 6000-10% (NH4)2SO4. When ATPS fraction from Red Lady cultivar was further precipitated with 40-60% saturation of (NH4)2SO4, PF of 2.1-fold with 80.23% yield was obtained. Almost all offensive odorous compounds, particularly benzyl isothiocyanate, were removed from partially purified glycyl endopeptidase (PPGE). The fish gelatin hydrolysates prepared using PPGE showed higher ABTS radical scavenging activity and less odour, compared with those of crude extract (CE). Thus antioxidative gelatin hydrolysate with negligible undesirable odour could be prepared with the aid of PPGE.

Production of Antioxidative Maillard Reaction Products from Gelatin Hydrolysate of Unicorn Leatherjacket Skin

ABSTRACT Antioxidative activities of Maillard reaction products (MRPs) derived from gelatin hydrolysate (GH) of unicorn leatherjacket skin as affected by types of saccharides, GH to saccharide ratio, incubation temperatures, relative humidity (RH), and times were investigated. MRPs prepared using mixture of GH and galactose at 2:1 (w/w) ratio showed the highest antioxidative activity. At different incubation temperatures (50–70°C) and RHs (55–75%), optimal condition for preparing antioxidative MRPs included heating GH and galactose (2:1) powder at 70°C and 55% RH for 36 h. Electrophoresis and Fourier transform infrared spectroscopy revealed the formation of high molecular weight polymers, and the advanced glycation took place in MRPs.