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Nanoparticles can be prepared by several sophisticated processes but until now, it cannot be prepared by simple home cooking. Here, we report that two incidental food nanoparticles (iFNPs) consisting of proteoglycans and phytosterols were isolated from soup made from freshwater clam (Corbicula fluminea Muller), a renowned folk remedy for liver problems in China and other parts of East Asia. These two bioactive iFNPs were obtained and characterized by anionic exchange chromatography coupled with multi-angle laser light scattering measurement. Their hydrodynamic diameters and ζ-potentials were 50 ± 0.2 nm and -28.0 mV and 67 ± 0.4 nm and -9.96 mV, respectively. FT-IR revealed that the proteoglycans in the particles contained α-type heteropolysaccharides. Both iFNPs were resistant to pH changes and separation by mechanical force but responsive to temperature changes. They effectively inhibited cholesterol uptake in vitro, which resonates with the traditional belief that freshwater clam soup provides hepatoprotective benefits. This study suggests that these two proteoglycan-lipid iFNPs are the active moieties and offers a supramolecular structure-based approach to study the function of such complex matrices derived from food.

Nanoparticles can be prepared by several sophisticated processes but until now, it cannot be prepared by simple home cooking. Here, we report that two incidental food nanoparticles (iFNPs) consisting of proteoglycans and phytosterols were isolated from soup made from freshwater clam (

The main edible portion of a marine animal is composed of the largest muscles of the body. However, many other parts are also used as food, especially the skin, liver, milt, roe, the fins of shark, and the alimentary tract of squid. The hydration of proteins is responsible for the rheological properties and juiciness of muscle foods. In tables of food composition, the content of proteins refers usually to the crude protein. Among the sarcoplasmic enzymes influencing the quality of fish as food are mainly the enzymes of the glycolytic pathway and the hydrolytic enzymes of the lysosomes. The nutritive and commercial value of various fish and marine invertebrates depends on the structure of the flesh and other edible parts, on the proportions of these parts in the total mass of the specimen, on the chemical composition of the meat, gonads, liver, etc., and on factors related to fishing and handling procedures.

Commercial diets containing α-tocopherol (90mg/kg) were supplememted with O, 100 and 200 mg/kg a-form vitamin E acetate respectively and fed to one-year-old (1+) grey mullet (Mugil cephalus )for 12 months. Plasma vitamin E increased as dietary vitamin E increased, and showed seasonal changes. It decreased from May to Novemder, then gradually increased until the following February. Vitamin E content in ovary was the lowest (296-376μg/g lipid) in October and the highest (602-694μg/g lipid) in November, then decreased to 408-453μg/g lipid in December. A negative relationship between vitamin E contents in plasma and in ovary was observed. Grey mullet erythrocytes appeared ellipsoidal in shape with a major axis of 9.24 to 9.88μm and a minor axis of 6.33 to 6.67μm. No significant difference was found in shape and size of erythrocytes from grey mullet fed with diets of different vitamin E levels. Spontaneous hemolysis was 7.55-7.71%in an 8 h test, regardless of the dietary vitamin E intake of the fish. Body and ovary weights were significantly lower for mullet fed on commercial diets than fed on diets supplemented with vitamin E to 190 and 290mg/kg.

An economic, simple and sensitive enzymatic method for the determination of copper in aqueous samples was proposed in this study. By removal of copper, superoxide dismutase (SOD) becomes apoenzyme SOD (apo-SOD) that has no SOD activity. The amount of copper added can be estimated by the recovery of SOD activity from reconstituted apo-SOD. The concentration of copper in an aqueous sample can thus be determined. A linear relationship (R^2 = 0.998) between the concentrations of copper, ranging from 20 to 80 ppb, and the recovered SOD activities was observed. The detection limit tor copper in the proposed assay was 20 ppb. Moreover, interfering effects of some common metal s on the recovery of SOD activity was evaluated. It showed that the concentrations of these metals less than 45μg/mL exhibited no interference in the assay. In addition, data obtained from this assay were very close to those estimated by inductively-coupled plasma atomic emission spectrometry (ICP-AES). This enzymatic method can be adapted as a routine assay for the determination of copper in aqueous samples such as beverages, drinking water and liquid foods. The assay can be applied for large number of samples (about 96 samples per hour) on an ELISA microplate reader.

Different antioxidant measurements, including the inhibition of linoleic acid autoxidation, scavenging effect on, α,α-diphenyl-β-picrylhydrazyl free radical, reducing power, and chelating abilities of metal ions Cu(superscript 2+) and Fe(superscript 2+), showed that the extract of chicken essence possessed antioxidant activities. The antioxidant activity increased with increasing concentration. Chicken essence contained a considerable amount of free amino acids, of which taurine was the predominant compound. Low-molecular-weight peptides were also present in a large quantity. An extraordinary feature was that the product contained high levels of potent antioxidants, anserine and carnosine. Three antioxidant peptide fractions of chicken essence were separated by size exclusion chromatography. The peptide with molecular weight of approximately 1400 Da possessed the strongest antioxidant activity followed by peptides with 900 and 500 Da. Two antioxidant peptides were further isolated and identified, and their amino acid sequences were His-Val-Thr-Glu-Glu and Pro-Val-Pro-Ala-Glu-Gly-Val. respectively.

Freshwater clams (Corbicula fluminea) have long been used as a folk remedy in Chinese tradition. Their hot-water extract has been commercialized as a functional drink for liver protection. The objective of this study was to develop a product of the residual clam meat (FCR) and assess its functional compounds. The ethanol extract of FCR, designated FCRE, was identified to comprise phytosterols, polyunsaturated fatty acids (PUFAs) and carotenoids. FCRE significantly reduced lipid accumulation and cell death in HepG2 cells via decreased fatty acid synthase (FAS) activity and increased activities of carnitine palmitoyltransferase (CPT) and acyl-CoA oxidase (ACO), indicative of suppressed lipogenesis and increased β-oxidation of fatty acids. In tilapia fed with high-fat diet (HFD), FCRE mitigated nonalcoholic steatohepatitis (NASH), which was evidenced by decreased levels of plasma aspartate transaminase (AST) and alanine transaminase (ALT), in addition to reduced total cholesterol and accumulation of triacylglycerols, particularly those of saturated and monounsaturated fatty acids. FCRE also suppressed stearoyl-CoA desaturase-1 (SCD-1) index, increased the PUFAs' n3/n6 ratio, and reduced prostaglandin E2 (PGE2) and inflammatory infiltrates in tilapia liver. Tilapia fed with HFD for 2 weeks displayed NASH symptoms, while mice took 10 weeks to display NASH symptoms. No previous study has been reported on the potential use of tilapia as an NASH model for pre-screening hepatoprotective-functional foods.

Acid-soluble collagen (ASC) was extracted from the skin and meat of orbicular batfish (Platax orbicularis) cultured in deep-sea water (DSW) and shallow-sea water (SSW). The fish cultured in deep-sea water contained higher collagen content (42.14 mg/g) in meat than that cultured in shallow-sea water (33.67 mg/g) (p

Multiple stressors associated with live fish transport, such as shaking, packing, hyper‑oxygenation, and cold stress, present a growing concern for fish welfare. The current study was designed to evaluate the fish welfare promoting effects of I-Tiao-Gung extract (Glycine tomentella, GTE), an extract derived from a Chinese herb, during live transport of blood parrot cichlid (Amphilophus citrinellus x Cichlasoma synspilum) and koi (Cyprinus carpio). The study analyzed plasma electrolytes, glucose, lactate, and cortisol levels from blood of both fishes during simulated transport. Results showed that adding GTE in water significantly decreased cortisol levels in blood parrot cichlid after 2–6 h and in koi after 4–6 h of simulated transport, respectively. Levels of glucose, lactate, and K+ in blood parrot cichlid began to elevate significantly between 2 and 6 h under stress. While levels of blood Na+, Ca2+ and lactate of koi significantly increased after simulated transport. Interestingly, Cl− levels were depressed significantly upon stress in both fishes. An indirect approach using ventilation frequency (VF) to gauge metabolism was taken to assess the physiological effects. VF was significantly slower in blood parrot cichlid after GTE addition comparing to that of the control group, but the effect was not significant in koi. Therefore, addition of GTE mitigated transport stress responses in both ornamental fishes through down-regulation of cortisol; thereby, promoting fish welfare during live transport.

Tilapia were used as an alternative animal model for evaluating metabolic syndrome, e.g., hyperlipidaemia and hypercholesterolaemia. Vascular lipid accumulation and inflammation of tilapia were induced by a high-fat diet (HFD) given for two weeks. The HFD triggered lipid peroxidation, high concentrations of total cholesterol and low-density lipoprotein (LDL) cholesterol in plasma, leading to hyperlipidaemia, fatty liver, and lipid accumulation in aorta intima. Tilapia fed an HFD supplemented with freshwater clam extracts (FCEs) showed improved plasma lipid profiles, reduction of liver size and decreased lipid accumulation in the liver. FCEs also enhanced plasma antioxidant status and alleviated vascular lesions in the tilapia fed an HFD. In vivo experimental results proved the atherosclerosis-preventive properties of FCEs against oxidative stress on lipid metabolism. Consequently, FCEs may serve as a potential nutraceutical ingredient to reduce the risk factors of cardiovascular diseases.

Benthosema pterotum is an underutilized deep-sea by-catch fish. Its protein hydrolysate (BPH) showed antioxidative activity. The BPH consisting of 13.2 mg/g of active peptides, Phe-Tyr-Tyr and Asp-Trp, significantly reduced H 2 O 2 -induced reactive oxygen species (ROS) and apoptotic cell death in human neuroblastoma SH-SY5Y cells through activation of intracellular antioxidant defence system. In Morris water-maze test, BPH was able to ameliorate memory and learning deficiency of D-galactose (D-gal)-induced neurodegenerative/ageing ICR mice. BPH-fed mice showed significantly lower levels of both D-gal-induced thiobarbituric acid reactive substances (TBARS) and endothelial nitric oxide synthase (eNOS), but higher levels of glucose-6-phosphate dehydrogenase (G6PDH) and brain-derived neurotrophy factor (BDNF) in brain of ageing mice in comparison to the control. In light of these results, BPH may be considered as a novel nutraceutical for easing the ageing and/or age-related neurodegenerative diseases.

Live fish transport has been an uprising research subject. A natural extract of Glycine tomentella (GTE) called I Tiao Gung in Chinese, which had antioxidant and anti-inflammatory activities was able to reduce stress responses during live grouper transport. An effective dosage in packing water decreased transport stress of grouper resulted in 100% survival rate at 18 juvenile grouper/L water, while without GTE the maximal stocking density achieved was 12 juvenile grouper/L. When the stocking density was 16 juvenile grouper/L, or 3 adult grouper/L, addition of 250 μg/L GTE in packing water resulted in reduced plasma cortisol level, increased SOD activity, reduced lipid peroxides of grouper, and stabilized water quality indicated by increased dissolved oxygen (DO) and reduced total ammonia nitrogen (TAN) measured 4 to 6- h of simulated transport. PO2 levels of grouper stocked in GTE-added packing water and shake as simulated transport (Treatment Group) was significantly (p

Proteins from tilapia frame and skin can potentially be precursors of antihypertensive peptides according to the result of BIOPEP analyses. The aim was to generate peptides with inhibitory effects against angiotensin-converting enzyme (ACE) and renin from tilapia frame and skin protein isolates (FPI and SPI). The most active hydrolysate was then tested for blood pressure-lowering ability in spontaneously hypertensive rats (SHRs). Tilapia frame and skin protein hydrolysates (FPHs and SPHs) were respectively produced from FPI and SPI hydrolysis using pepsin, papain, or bromelain. The ACE-inhibitory activities of tilapia protein hydrolysates with varying degree of hydrolysis (DH) were evaluated. In order to enhance the activity, the hydrolysate was fractionated into four fractions (

This study aimed to identify the bioactive compounds and evaluate the anti-cold-stress function of the sorghum distillery residue (SDR) using tilapia as an alternative animal model. The highest contents of water-soluble bioactive compounds in SDR were polyphenols, followed by tannins, anthocyanins, and flavonoids. SDR was extracted with double-distilled water, 95% ethanol, and ethyl acetate, separately. The ethanol extract (SDR-E) yielded the highest polyphenol content [15.03 mg/g of SDR dry weight (dw)], of which the EC50 value of R,R-diphenyl-β-picrylhydrazyl (DPPH) radical scavenging efficiency was 0.56 ± 0.04 mg/mL. The SDR-E suppressed the oxidation of low-density lipoproteins (LDLs) more efficiently than that of other extracts. Tilapia fed a diet containing 3.6% SDR-E decreased accumulative mortality during cold stress, of 46.2%. The accumulative morality of the control was 92.9%. The phenolic acids identified in SDR included gallic acid (0.36 ± 0.08 mg/g of SDR dw), 3,4-dihydroxybenzoic acid (0.16 ± 0.12 mg/g of SDR dw), and 4-hydroxybenzoic acid (0.49 ± 0.23 mg/g of SDR dw). Diets supplemented with 0.5% 4-hydroxybenzoic acid fed to tilapia showed a lower mortality rate than that fed 1.0% 4-hydroxybenzoic acid, comparable to that of the tilapia fed 20% SDR. The latter showed lower mortality than that of the control. These results suggested that 4-hydroxybenzoic acid is one of the major anti-cold-stress compounds in SDR.

What is Behind Capture and Handling the Catch? E. Grazyna Daczkowska-Kozon World Seafood Resources and Seafood Consumption, Jolanta Zieziula and Edyta Pawlak Seafood Quality Issue, Zdzislaw E. Sikorski and Edward Kolakowski Environmental Limitations and General Impact on Properties of the Catch, Stephen T. Grabacki Onboard Quality Systems, Stephen T. Grabacki Quality of Seafood from Aquaculture, Bonnie Sun Pan Benefits of Seafood Consumption, Yun-Hwa Peggy Hsieh and Bahram Arjmandi Safety Aspects of Seafood, Elzbieta Daczkowska-Kozon, Waldemar Dabrowski, Agnieszka Bednarczyk-Drag, and Barbara Szymczak Allergens, Elzbieta Kucharska, Joanna Bober, and Tadeusz Ogonski Abiotic Environmental Factors Affecting Seafood Safety and Properties, Agnieszka Torz, Arkadiusz Nedzarek, Teresa Radziejewska, and Maciej Kielpinski Biotic Environmental Factors Affecting Seafood Quality, Teresa Radziejewska Anthropogenic Environmental Factors Affecting Seafood Safety and Properties, Shiu-Mei Liu, and Bonnie Sun Pan Seafood Quality Assurance for Algal Toxins, G. M. Hallegraeff Bacteria on Seafood: Friend or Foe, E. Grazyna Daczkowska-Kozon Fish and Shellfish Diseases and Seafood Quality, Ewa Sobecka and Wojciech Piasecki Influence of Global Warming on Seafood Availability, Fu-Sung "Frank" Chiang and Chin-Hwa "Jenny" Sun Sea Fish and Shellfish Authentication Issues, Wojciech Sawicki and Dagmara M. Klein Understanding Seafood Quality and Freshness Issues Across the Globe, H. Allan Bremner Tracing the Catch through the Chain, Olga Szulecka How Improved Logistics can Improve the Standards of Seafood in the Supply Chain, Wojciech Brocki, Roman Drozdowski, and Stanislaw Kasperek Sustainable Seafood Fishing and Farming, Bohdan Draganik What Could be Done for Better Seafood Availability, Quality, and Safety, E. Grazyna Daczkowska-Kozon

The fatty acid compositions of 21 species of marine macroalgae, including 5 species of Chlorophyta (green algae), 13 of Rhodophyta (red algae), and 3 of Heterokontophyta (brown algae), were collected from northeastern Taiwan to survey their functional lipids. The lipid contents of green algae ranged from 15.36 to 20.15 mg/g, dry basis (db), and were characterized by a high content of C18:2 and C18:3, red algae (18.57-28.34 mg/g db) were high in C20:4 and C20:5, and brown algae (13.11-19.56 mg/g db) were high in C18:4, C20:4, and C:20:5. All algal lipids contained fatty acids of odd-number carbons, C17:0, and C17:1. Red algae had relatively higher levels of polyunsaturated fatty acids (PUFAs) and were richer in eicosapentaenoic acid (EPA) than green and brown algae. A red alga, Porphyra crispata , was extracted with ethanol and separated on a hydrophobic column (Diaion HP-20 column) to obtain sulfoglycolipids (sulfoquinovosyldiacylglycerols, SQDGs). The main fatty acids in SQDGs were palmitic acid (C16:0), 33.3%; EPA (C20:5), 30.0%; arachidonic acid (C20:4), 12.7%; oleic acid (C18:1), 7.52%; and stearic acid (C18:0), 6.83%. The n-3/n-6 ratio was 1.9, whereas the authentic standard, spinach SQDG, did not contain n-3 fatty acids. Sulfoglycolipids inhibited the growth of human hepatocellular carcinoma cell line (HepG2). The IC50 was 126 μg/mL, which is lower than that of the spinach SQDG (255 μg/mL).

Purification and characterization of keratinase from Meiothermus sp. I40, a newly identified strain isolated from hot springs, was carried out and reported. Crude enzyme was obtained from culture medium after incubation of I40 for 2 days and was purified by 20–80% precipitation with (NH 4 ) 2 SO 4 , and separated by hydroxyapatite and Superdex pg 200 gel filtration chromatography. The overall recovery of enzyme activity was 45% with a 30.2-fold after purification. The molecular mass of the purified enzyme was 76 kDa with K m and V max of 0.29 mM and 1428.6 U/mg-min, respectively. The optimum pH and temperature of the keratinase I40 was 8.0; and 70 °C, respectively. When incubated at 65 °C and 70 °C for 12 h, the enzyme retained 96.7% and 71.3% of the activity, respectively. The purified enzyme was completely inhibited by phenylmethanesulfonyl fluoride (PMSF), indicating that keratinase I40 is a serine protease. Keratinase I40 exhibited good stability in the presence of dimethyl sulfoxide, ethanol, isopropanol and acetonitrile. The enzyme showed the highest activity toward chicken feather, followed by dove feather, duck feather, human hair, wool, and hog bristle. Chicken feathers treated with keratinase I40 were fully degraded in one days, but no change was detected with seven common proteases. The molecular weight (MW) of the peptides released from chicken feathers after treatment with keratinase I40 ranged from 0.48 to 10 kDa with an average of 1.84 kDa. Keratinase I40 seems to be an efficient and environmentally friendly enzyme in the biodegradation of feather keratin.

The objective of this study was to elucidate the in vivo effects of the ethanol extract of wooly Glycine tomentella Hayata (GTE) root on tilapia to elucidate whether GTE has antistress activity. Tilapia as an animal model were fed with or without GTE, then injected with lipopolysaccharide (LPS) or ammonium chloride (NH(4)Cl). The tilapia were exposed to 100 mg/L of aqueous NH(4)Cl, and/or acute cold stress. Growth parameters of the tilapia were measured during the feeding trials. Tilapia injected with GTE (20 μg/g of fish), NH(4)Cl (100 μg/g of fish) and/or LPS (1 μg/g of fish) were then sampled 2 h poststimulation. GTE significantly inhibited cyclooxygenase-2 expression and hemoglobin (Hb) dimer formation (36 kDa). GTE also improved growth and blood viscosity and upregulated eicosapentaenoic acid content of erythrocytes. The in vivo results indicated that GTE (20 μg/g of fish) can be applied as a stress-tolerance enhancing agent for the aquaculture industry.

Tetramethylammonium hydroxide (TMAH)-catalyzed transesterification was developed as a rapid and reliable method using gas chromatography (GC) to determine the total fatty acid profile and to quantify the ethyl esters of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in 20 brands of encapsulated fish oil products. The AOAC method with boron trifluoride (BF3) as a catalyst was used as a reference. After the respective transesterifications of BF3 and TMAH, seven brands of encapsulated fish oil showed a single peak of EPA or DHA in the chromatograms, while 13 brands showed a single peak in the chromatograms after BF3 esterification, but doublet peaks of EPA or DHA after TMAH esterification. By comparing with the GC/MS NIST library and authentic standard fatty acids of ethyl esters, the two pairs of doublet peaks were confirmed the ethyl and methyl esters of EPA and DHA, while the sum of the peak areas of the doublet represented the content of EPA or DHA. The reaction time course concluded that optimal TMAH transesterification was obtained at 25 °C for 10 min and using GC columns of low to medium polarity including Rtx-wax and Rtx-2330 were able to differentiate and quantify the ethyl- and methyl-esterified EPA and DHA, while RT-2560 column with higher polarity than the two other columns was unable to resolve the ethyl ester from the methyl ester of EPA or DHA. An EPA/DHA ratio of ≥1.10 may serve as an indicator of fish oil fortified with the ethyl ester of EPA.

This study investigates the hypocholesterolemic effects of a diet containing freshwater clam hydrolysate (PX) and insoluble dietary fibre from whole Gracilaria (IDF). Freshwater clam meat and whole dried Gracilaria were separately extracted using hot water. The residual meat was hydrolysed at 50 °C by Protamex to obtain freshwater clam hydrolysate (PX). Levels of triacylglycerol and cholesterol in Sprague–Dawley (SD) rats were compared with those of rats fed diets containing casein and cellulose as a control. Plasma triacylglycerol levels decreased by 65.8%, 27.9%, and 44.3%, respectively, in PX10 (16.6% hydrolysate), IDF10 (13.0% IDF) and compounded PX10/IDF10 groups, while plasma total cholesterol levels decreased by 26.1%, 24.2%, and 17.1%, respectively. In the liver, triacylglycerol levels decreased by 27.6%, 21.0%, and 28.0%, respectively, while total cholesterol levels decreased by 50.0%, 38.5%, and 48.6%, respectively. The compound PX10/IDF10 diet group showed a higher excretion of faecal total cholesterol and bile acids levels than did the other groups.

The objective of the present study is to purify and characterize the fish scale-degrading enzyme from Vogesella sp.7307-1, which was newly identified and isolated from fish scales. The enzyme from Vogesella sp.7307-1 was assayed with casein and confirmed as a protease. Crude protease was extracted, isolated, and purified 35.7-fold with 19.6% recovery using 20-80% saturation of ammonium sulfate fractionation, Q FF ion exchange chromatography, and Superdex 200 gelfiltration. The molecular weight of the purified enzyme was 119 kDa. The Km and Vmax were 0.067 mM and 425.5 U/mg-min, respectively using azo-casein as substrate. The optimum pH of the purified enzyme was 7.5, and the optimum temperature was 50 °C. The enzyme was stable at temperatures below 55 °C and pH range 7.5 to 9.0. The enzyme activity of the purified protease was completely inhibited by EDTA (ethylene diamine teraacetates), indicating the enzyme was a metalloprotease. Hydrolysates from fish scales treated with protease 7307-1 were found having low molecular weight peptides (1 kDa). The protease 7307-1 is a promising enzyme for preparing smaller peptides from fish scales.

The muscles of freshwater clam and whole Gracilaria powder (WG) were separately extracted using hot water. The residual meat was first freeze-dried, then hydrolysed at 50 °C by Protamex to obtain freshwater clam hydrolysate (PX5). The WG was separated into two fractions, designated as soluble (SDF) and insoluble dietary fibre (IDF). The in vitro bile acid-binding capacities and inhibition of micellar solubility of cholesterol were then investigated using the compounded PX5 and dietary fibre of WG or IDF. Assuming that bile acid binds to cholestyramine at 100%, the relative bile acid-bindings of PX5 and WG were 35.9% and 41.1%, respectively. Bile acid-binding of compounded PX5 and WG showed the best synergistic effect at a ratio of 1:3 (w/w) and relative bile acid-binding of 45.7%, significantly higher than PX5 and WG alone. After peptic digestion, the resulting inhibitions against cholesterol micelle formation in cholestyramine, PX5, WG and IDF were 97.6%, 18.5%, 30.8% and 49.3%, respectively.

The lipoxygenase (LOX) of the marine green alga Ulva fasciata was purified and immobilized in order to improve the stability and reusability. The algal LOX was partially purified by fractionation with 35–55% saturation of ammonium sulfate and MacroPrep high Q anion exchange chromatography. The LOX was purified ten times using linoleic acid (C18:2) or arachidonic acid (C20:4) as substrate, the Michaelis constant (K m) of LOX was 117.6, 31.3 μM, and maximum velocity (V max) was 12.8, 23.3 μmol hydroperoxy fatty acid/min-mg protein, respectively. The algal LOX showed the highest activity towards C18:4 followed by C20:4, C18:2 and methyl ester of C18:4. LOX activity increased up to 10.5 times with increased concentration of Triton X-100 in the extraction medium reaching an optimum at 0.05%. Calcium chloride, glutathione and phenylmethylsulphonyl fluoride were found effective protectants to LOX during purification. Hydroperoxyeicosatetraenoic acid (HpETE) formed from arachidonic acid catalyzed by this purified algal LOX was reduced and identified as 11-hydroxy-5,8,12,14-eicosatetraenoic acid (11-HETE) by NP-HPLC and GC–MS. This algal 11-LOX was immobilized in alginate beads. The stability was sevenfold greater than that of the unbound lipoxygenase at 4 °C in 0.05 M Tris–HCl buffer (pH 7.5). This is the first report on immobilization of a marine algal lipoxygenase with a view to its potential role in seafood flavor formation.

The meat of hard clam was extracted using hot water. The residual meat was freeze-dried then hydrolyzed at 50 °C for 5 h by Protamex (PX). The inhibitory effects of hot water extract and hydrolysate against angiotensin I converting enzyme (ACE) were investigated. The IC 50 value of hot water extract and hydrolysate on ACE were 1.090 and 0.036 mg/ml, respectively. The PX hydrolysate was separated into five fractions by size exclusion chromatography on a Sephadex G-25 column. The fifth fraction of the hydrolysate having molecular weight ranged 350–300 Da showed the highest inhibitory efficiency ratio (IER) being 5831%/(mg ml). The amino acid sequence of the inhibitory peptide was Tyr-Asn (IC 50 = 51 μM). The hydrolysate showed mixed-type inhibition kinetics while Captopril, the positive control, showed competitive inhibition on ACE. Their K i values were 0.027 mg/ml and 0.0067 μg/ml, respectively.

Milk was fermented for up to 5 h at 43 °C with two lactic acid bacteria (Streptococcus thermophilus, Lactobacillus bulgaricus). A protease, flavourzyme, was added at the beginning of fermentation. The whey fraction was separated from the fermented milk and freeze-dried. During the 5 h of fermentation, the soluble protein content increased from 4.9 to 57.4 mg/g and peptide content increased from 2.1 to 32.8 mg/g, while inhibition of angiotensin I-converting enzyme (ACE) increased by a decrease of IC50 from 0.708 to 0.266 mg/ml, respectively. The whey was fractionated into four fractions by size exclusion chromatography on a Sephadex G-15 column. The fourth fraction of the whey showed the highest inhibitory efficiency ratio (IER) being 1329%/mg/ml. The amino acid sequence of the inhibitory peptide was Tyr-Pro-Tyr-Tyr, of which the IC50 was 90.9 μM. The whey showed mixed-type inhibition kinetics, while Captopril, the positive control showed competitive inhibition on ACE. Their Ki values were 0.188 mg/ml and 0.0067 μg/ml, respectively. The systolic blood pressure (SBP) and diastolic blood pressure (DBP) was reduced to 15.9 and 15.6 mm Hg, respectively, in spontaneously hypertensive rat (SHR), after 8 weeks of oral administration of diluted whey (peptide concentration 4.9 mg/ml).

Fresh low-fat milk was fermented for up to 30 h at 42C with five mixed lactic acid bacteria. A protease, Prozyme 6, was added 5 h after the beginning of bacterial fermentation. The whey was separated from the fermented milk and freeze-dried. As the fermentation time extended to 30 h, the inhibition of lipoxygenase increased as indicated by a decrease of IC50from 3.79 to 0.47 mg powder/mL. The relative percentage of binding bile acid by whey was 39.3% in comparison to cholestyramine. Inhibition of angiotensin I-converting enzyme increased as shown by a decrease of IC50 from 1.18 to 0.24 mg powder/mL. The systolic blood pressure and diastolic blood pressure were reduced 22.6 and 21.5 mmHg, respectively, in spontaneously hypertensive rat, after 8 weeks of oral administration of diluted whey (12.5 mg powder/mL). PRACTICAL APPLICATIONS A new technique was developed in this experiment using a combination of lactic acid bacteria fermentation and protease hydrolysis to accelerate the production of bioactive peptides from fresh low-fat milk. The fermented whey product exhibited in vitro inhibition on lipoxygenase (LOX) and angiotensin I-converting enzyme, and reduced the LOX-catalyzed low-density lipoprotein oxidation. The whey product also showed higher bile acid binding capacity; thus, it might possibly have the potential of reducing serum cholesterol in vivo. Also, in vivo antihypertensive effect was confirmed on spontaneouosly hypertensive rat by long- or short-term administration. This fermented milk whey was expected to be a useful ingredient in physiologically functional foods for reduction of cardiovascular disease risk.

The ethanolic extract of I-Tiao Gung (GT-E) (Glycine tomentella root extract) was found to reduce the oxidative rate and prolonged lag phase of LDL in human (Homo sapiens) and tilapia (Oreochromis mossambicus). The in vivo effect of GT-E was determined using tilapia as a model. Hyperlipidemia and hypercholesterolemia were induced in fish by feeding commercial feed daily at 2% body mass for 8 weeks, or at 1% body mass for 12 weeks. Thirty two adult male tilapia were randomly divided into two groups and fed with feed containing 1% (w/w) GT-E or control diet for 12 weeks. Specific growth rate was similar between the GT-E group and the control group. Total triacylglycerol, total cholesterol and low-density lipoprotein cholesterol (LDL-C) in plasma of the GT-E group were significantly lower, while plasma total antioxidant status was significantly higher than those of the control group. GT-E fed fish had longer lag phase of Cu2+-induced LDL oxidation and retained more alpha-tocopherol in LDL particles than the control fish. LDL from the GT-E group had more monounsaturated fatty acids and less polyunsaturated fatty acids than the control group indicative of its effect on fatty acids metabolism. GT-E demonstrated hypolipidemic and hypocholesterolemic effects and inhibiting LDL oxidation in tilapia similar to the effects in mammals, thus tilapia can serve as a surrogate animal model for prescreening anti-atherosclerosis effect of natural products.

Summary Processing data was obtained for the freezing of tilapia meat. The initial freezing point of tilapia meat was measured by differential scanning calorimetry (DSC), and also by measuring the centre temperatures of meat chunks during cooling. the freezing point was −1.03°C by DSC, and between −0.81 and −0.90°C by the cooling method, determined at the point where the standard deviation of the mean temperature was close to zero, i.e. a minimum. Tilapia chunks, 0.95 to 1.45 cm thick, were frozen in an airblast freezer at −7, −20 and −36°C, and in a liquid nitrogen freezer at −87 and −128°C. Freezing rate, defined as the half thickness of a meat chunk divided by the time for the centre temperature to decrease from 0 to −5°C, was 0.09 cmh−1 at −7°C. At freezing temperatures of −20, −36, −87 and −128°C, the rates were respectively 4, 19, 158 and 331 times faster than that at −7°C, and correlated with freezing temperature (r= 0.99) regardless of the freezing method.

Fresh low-fat milk was fermented with five mixed lactic acid bacteria for up to 30 h at 42 °C. A protease, prozyme 6, was added 5 h after the beginning of fermentation. The whey was separated from the fermented milk and freeze-dried. As the fermentation time extended to 30 h, soluble protein content increased from 30.9 to 195.9 mg g−1, free amino acid content increased from 2.8 to 192.8 mg g−1, peptide content increased from 6.4 to 402.8 mg g−1 and γ-aminobutyric acid (GABA) increased from 0 to 80.6 mg 100 g−1, while inhibition of angiotensin I-converting enzyme (ACE) increased as indicated by a decrease of IC50 from 1.18 to 0.24 mg mL−1, respectively. The amino acid sequences of two ACE inhibitory peptides were Gly–Thr–Trp and Gly–Val–Trp, of which the IC50 values were 464.4 and 240.0 μ m , respectively. The systolic blood pressure and diastolic blood pressure of spontaneously hypertensive rat (SHR) were reduced 22 and 21.5 mm Hg, respectively, after 8 weeks of oral administration of diluted whey (peptide concentration 5 mg mL−1) from the 30 h fermentation.

Hard clams (HC), Meretrix lusoria are a popular seafood and traditionally used as a Chinese remedy for liver disease and chronic hepatitis. The goal of this study was to identify compounds from hard clam, which are responsible for inducing apoptosis using bioassay-directed isolation. The effects of ethyl acetate extract of HC (HC-EA) on cell viability in human cancer cells were investigated. The ethyl acetate fraction was then subjected to separation and purification using silica gel column chromatography. The compounds showing strong apoptosis inducing activity were identified by spectral methods as epidioxysterols (EDS). The molecular mechanisms of epidioxysterolds-induced apoptosis as determined by annexin V apoptosis assay, DNA condensation, and sub-G1 DNA were investigated. The results suggest that induction of apoptosis by epidioxysterols may provide a pivotal mechanism for its cancer chemoprevention.

The muscle of golden freshwater clam was extracted using hot water. The residual meat was freeze-dried then hydrolyzed at 50 °C first by Protamex (PX) as primary hydrolysis followed by a secondary hydrolysis (Flavourzyme, F). The inhibitory effects of hot water extracts and hydrolysates against angiotensin I converting enzyme (ACE) were investigated. The soluble protein content and peptide content of the hot water extracts was 85 and 84 mg/g, respectively. The IC50 on ACE was 1.95 mg/ml. The highest values of soluble protein (571 mg/g) and peptide content (272 mg/g) of hydrolysate prepared by PX hydrolysis for 5 h (PX5) or PX hydrolysis for 5 h followed by F hydrolysis for 0.5 h (PX5F0.5). PX5 showed the lowest IC50 on ACE (0.043 mg/ml), and a mixed-type inhibition kinetics while Captopril showed competitive inhibition. Their Ki values were 0.032 mg/ml and 0.0067 μg/ml, respectively. The PX5 hydrolysate was fractionated by size exclusion chromatography on a Sephadex G-25. A fraction of the PX5 had molecular weight ranged 420–380 Da showed the highest inhibitory efficiency ratio (IER) being 1314.7%/mg/ml. The amino acid sequences of the two peaks of this fraction PX-D1 and PX-D2 were Val-Lys-Pro and Val-Lys-Lys, of which IC50 value were 3.7 and 1045 μM, respectively. This freshwater clam hydrolysate (PX5) (peptide concentration 5 mg/ml) was used as drinks administered to spontaneously hypertensive rats (SHR) for 8 weeks. The systolic blood pressure and diastolic blood pressure of the SHR were significantly reduced by 22.0 and 13.2 mmHg, respectively, indicating a hypotensive effect by oral administration.

Soymilk was fermented with five lactic acid bacteria (Lactobacillus casei, Lactobacillus acidophilus, Streptococcus thermophilus, Lactobacillus bulgaricus, Bifidobacterium longum) for up to 30 h at 42 °C. A protease, prozyme 6, was added 5 h after fermentation. The whey was separated from the fermented soymilk and then freeze-dried. As the fermentation time extended to 30 h, pH decreased from 6.5 to 4.1, soluble protein content increased from 47 to 390 mg/g, free amino acid content increased from 91.3 to 214.4 mg/g, peptide content increased from 39.6 to 463.3 mg/g and γ-aminobutyric acid (GABA) increased from 93.9 to 361.6 mg/100 g, and inhibition of angiotensin I-converting enzyme (ACE) IC50 decreased from 9.28 to 0.66 mg powder/ml, respectively. Fermentation of whey for 30 h was fractionated by size exclusion chromatography on a Sephadex G-15 column. A fraction of 800–900 Da was found with the highest inhibitory efficiency ratio (IER) being 795%/(mg ml). This whey (peptide concentration 10 mg/ml) was used as drinks administered to the spontaneously hypertensive rat (SHR) for 8 weeks. The systolic blood pressure (SBP) of SHR reduced to 19.0 mmHg after 8 weeks of oral administration.

The anti-oxidative and anti-inflammatory activities of two different species of traditional Chinese medicines that shared the same name have been studied. The extracts of Glycine radix have higher activities in free radical-scavenging activity determined with DPPH, reduction in hemoglobin-catalyzed lipid auto-oxidation and inhibition of the lipoxygenase (LOX) and cyclooxygenase (COX)-catalyzed arachidonate oxidation compared to the activities of extract of Flemingia. One of the significant bioactive constituents of Glycine radix has been isolated and identified as daidzein.

Adipose fat tissue, which contributes 1.6–5.8% of total chicken carcass weight, has been underutilized by chicken processors because of its “chickenish odor.” The objective of this study was to prepare a chicken oil from which the undesirable odor notes were eliminated and in which the desirable volatile compounds were enhanced. Chicken adipose fat was dry-rendered at 140°C for 30 min and yielded 78.5% oil. Monoenoic FA constituted 55.8% of the chicken oil, and of that oleic acid constituted 92.8%. Treatment of chicken oil with an algal lipoxygenase extracted from Ulva spp. at 33°C for 30 min resulted in an increase of 0.40% in total monoenoic acids, a decrease of 33.3% in total polyenoic acids, and a decrease in total FA of 0.8%. A noticeable improvement in the odor of chicken oil after lipoxygenase treatment was observed by sensory evaluation and a GC-sniffing technique. The modified chicken oil contained more desirable volatile compounds—ethyl acetate, pentanal, 2-pentyl furan, E-2-heptenal, and nonanal—than the original chicken oil, provided fruity and tea-leaf aromas, and had reduced levels of the undesirable volatile compounds heptanal, 2,4-heptadienal, 2,4-nonadienal, and dodecanal. These modifications reduced the chickenish and oxidized odor notes.

Sorghum distillery residue (SDR) has antioxidant and blood thinning effect on fish fed during winter, but inhibited their growth. The objective of this study was to eliminate the adverse effect but to maintain the nutraceutical benefits of SDR. The content of tannin in SDR was found to be 3.3 mg/g on dry weight basis. An in vitro digestibility test was developed to simulate the in vivo digestion of grey mullet. The protein digestibility of SDR was 47% lower than that of the control. Inhibition of trypsin activity correlated with the amount of SDR extract (r = 0.98) and decreased significantly (P < 0.05) when the SDR extract was pretreated with polyethylene glycol (PEG), a tannin binding agent. Based on Lineweaver-Burk plot analysis, the inhibition of SDR on trypsin was of noncompetitive mixed type with changes in both Vmax and Km. A detannin treatment with PEG was tested. This treatment may provide an example to utilize other plant protein sources rich in tannin as fish feed ingredients.

A mechanical mullet roe drying process was designed to simulate the traditional intermittent sun drying-pressing process. A transient 3-dimensional diffusion equation was used to predict moisture content and moisture distribution using finite-difference techniques. Drying curves decreased in a logarithmic manner without a constant drying period from 25 °C to 40 °C. At the pressing stage, the moisture distribution became even and the drying rate increased during the subsequent drying stage as compared to the continuous drying curve at comparable drying time. Total drying time was effectively saved by 30% for 3 cycles of 12 h-12 h intermittent drying-pressing followed by continuous drying until the mullet roe reached a water activity (Aw) of 0.85.

The sorghum distillery residue (SDR) has been an underutilized by-product with estimated production of 150 ton/day in Kinmen, Taiwan. The objective of this study was to test for any physiological effects of SDR, thus to utilize it as a nutraceutical feed ingredient in diets for cultured fish. Hot air-dried, wet, and dehulled-wet sorghum distillery residue showed 63%, 90% and 97% inhibition of the hemoglobin-catalyzed oxidation of linoleic acid compared to soybean (13%) and rice bran (78%). The feed formulated with 20% wet or dehulled-wet sorghum distillery residue both showed an antioxidant activity of 68% being higher than the control diet (53%). Feeding these diets to cultured grey mullet for 60 days in summer (temperature ranged 24-30C), resulted in a lower hydroperoxide content in gill tissue, as shown by a chemiluminesence intensity of 1806 or 1409 mV as opposed to 2666 mV for fish fed a control diet. In winter, when the water temperature decreased to 14C, grey mullet fed a diet consisting of 10% dehulled wet sorghum distillery residue had a blood viscosity of 1.9 mPas and a hematocrit value of 33%, in contrast to 3.6 mPas and 41% for control. The blood of the control group started to aggregate in 6 h and showed hemolysis, while the mullet fed dehulled, wet sorghum distillery residue did not show blood aggregation, maintained normal fluidity and erythrocyte membrane integrity. It seems that cultured fish may have the potential as an animal model for prescreening antioxidant and blood thinning effects of food ingredients.

Fish oil is the major dietary source of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Adequate dietary intake of these n-3 PUFA is beneficial to reduce the risks of cardiovascular mortality, prostate cancer, and neurological disorders in children and adults. There is a surge in demand for fish oil in the functional food market. Microencapsulation of fish oil is the trend to improve its stability and sensory quality. The EPA and DHA content of the fish oil products may vary markedly from the label due to their susceptibility to oxidation. Quick and reliable methods other than the AOAC BF3 method have been exploited to quantify EPA and DHA in the encapsulated fish oil and the microencapsulated powdered products such as infant formula. This article describes a method to differentiate the ethyl-ester form from the TAG form of EPA and DHA in encapsulated fish oil which may be a mixture of natural triacylglycerol enriched with ethyl esterified EPA and DHA. A method is recommended due to the difference in apparent potency of these two esterified forms, which may be a concern in infant formula and elsewhere.