Macromineral and heavy metal profiles of selected deep-sea fish from the Kochi coast of the Arabian Sea, India.

Deep-sea fish from the Arabian Sea in the south western coast of India have been gaining attention as a new edible fish source. Mineral profile of ten selected deep-sea fish from the south west coast of India were assessed for heavy metal and macro mineral content for safety and nutritional quality assessment, respectively. Heavy metal levels were below permissible limits for most of the species studied. But in some species, the levels slightly exceeded the permissible limit of 0.3 mg/kg for Pb, a major heavy metal contaminant in fish, according to the European Union and FSSAI regulations for heavy metals in food. Interestingly, significant content of macro minerals was observed in all the species studied. In conclusion, deep-sea fish were observed to be good source of minerals and were found to be safe for human consumption; except for a couple of species which possess slightly higher Pb content, which may be because of its presence in their habitat.

Characterization of chitin extracted from enzymatically deproteinized Acetes shell residue with varying degree of hydrolysis.

Acetes shrimp is an unexploited tiny shrimp mainly landed as bycatch which is a good source for the recovery of protein and chitin. In the present study, the residual shell obtained after the hydrolysis of Acetes was used for the extraction of chitin by combining enzymatic and chemical treatments. Enzymatic hydrolysis with Alcalase was performed at different rates. Results showed that the protein removal efficiency increases with the increase in DH and the maximum deproteinzation was achieved at 30 % DH (93.68 %). The FTIR spectra showed two sharp bands for chemically prepared chitin and 30 % DH chitin at 1627-1629 and 1664-1665 cm-1 indicating that its alpha amorphous structure. The degree of N-acetylation was found to be higher in enzymatically prepared chitin in all different hydrolytic treatment rather than chemically prepared. The surface morphologies of chitin revealed the porous and nanofibrous structures for 30 % DH chitin and chemically prepared chitin.

Chitosan - Whey protein as efficient delivery system for squalene: Characterization and functional food application.

Squalene, a triterpenoid compound possessing excellent bioactivities, is not being utilized as a functional food ingredient due to its high susceptibility to oxidation. In the present study, the feasibility of chitosan-whey protein as an efficient wall material for squalene encapsulation using spray drying technique was attempted for functional food applications. The encapsulation efficiency of the squalene powder was found to be 75.4 ±â€¯0.22% whereas other physico-chemical properties such as moisture content, flowability, solubility, peroxide value, etc. have shown satisfactory results. The thermogravimetric analysis showed that chitosan-whey protein was able to retain the thermal stability of squalene up to a temperature of 422 °C. Furthermore, the functional food application of the encapsulated squalene in a bakery product (cake) exhibited significantly (p < 0.05) better properties in terms of oxidative stability, sensory attributes than that of cake with pure squalene and control treatment. Hence, it can be concluded that emulsification of squalene in chitosan-whey protein and its subsequent encapsulation by spray drying can be a potential process to produce oxidatively stable encapsulates for the development of functional foods.

Antioxidant, functional properties and amino acid composition of pepsin-derived protein hydrolysates from whole tilapia waste as influenced by pre-processing ice storage.

In recent years, hygienic handling of fishery waste is demanded owing to the fact that the fishery waste is an ideal raw material for the preparation of bioactive compounds. In the present study, the effect of pre-processing storage (at 4 ± 2 °C) of whole tilapia waste (WTW) on the properties of its protein hydrolysate derived using pepsin was evaluated. Fish protein hydrolysates (FPH) were prepared from 0, 24 and 48 h old ice stored WTW and designated as FPH-0, FPH-1, and FPH-2, respectively. Total amino acids, total essential amino acids and total hydrophobic amino acids of FPH samples increased with the storage period of raw material (WTW). Antioxidant activities such as DPPH (2, 2 diphynyl-1-picrylhydrazyl) free radical scavenging activity and ferric reducing power of FPH samples were dose dependent. FPH-0 had better antioxidant properties including linoleic acid peroxidation inhibition activity than FPH-1 and FPH-2. The DNA nicking assay revealed the protective effect of FPH preparations against Fenton's reaction mediated oxidative damage. FPH-2 had better emulsifying properties and foaming stability whereas the FPH-0 had relatively good foaming capacity. SDS-PAGE indicated the presence of peptides ranging from 116 to < 14.4 kDa in FPH-0 and less than 18 kDa in FPH-1 and FPH-2. The present study, clearly demonstrated that whole tilapia waste can effectively be converted to FPH and could be a potential ingredient in functional food and as a rich source of high-quality protein in animal feed formulations.

Evaluation of chitosan as a wall material for microencapsulation of squalene by spray drying: Characterization and oxidative stability studies.

The present study was aimed at investigating the efficacy of chitosan as a wall material for microencapsulation of squalene by spray drying for functional food applications. Based on different core to wall material ratio (1:1, 0.5:1 and 0.3:1 on w/w basis), emulsions were prepared and evaluated in terms of emulsion stability, particle size, zeta potential, polydispersity Index (PDI), rheology and microstructure. The optimized emulsion combination was spray dried and characterized, physically and chemically. The encapsulation efficiency of the powder was found to be 26±0.6% whereas other properties such as particle size, zeta potential, water activity, hygroscopicity, Carr Index, Hausner ratio have shown satisfactory results. SEM analysis showed that the squalene microcapsules were smooth spherical particles free from dents and fissures. FTIR data further confirmed the encapsulation of squalene with chitosan. However, TGA, oxidative stability and accelerated Rancimat results showed that chitosan was not able to protect squalene from oxidation during storage. The results suggest that chitosan is not an appropriate wall material for microencapsulation of squalene and hence a combination of wall materials could be attempted for the encapsulation of squalene.

Dietary supplementation of thiamine and pyridoxine-loaded vanillic acid-grafted chitosan microspheres enhances growth performance, metabolic and immune responses in experimental rats.

In the present investigation, the effect of dietary supplementation of thiamine and pyridoxine loaded vanillic acid-grafted chitosan microspheres (TPVGC) on growth, metabolic and immune responses in Wistar strain albino rats was studied. Eight experimental groups, namely four groups each for male and female rats were fed with 0, 0.4, 0.8 and 1.6% of TPVGC in the diet. At the end of 45days feeding trials, both male and female rats supplemented with TPVGC had higher weight gain% and specific growth rate than the control groups. Significantly (p<0.05) lower blood glucose level and higher respiratory burst activity were recorded in the treatment groups than the control groups of both male and female rats. Activity of metabolic enzymes (aspartate amino transferase, alanine aminotransferase, alkaline phosphatase and acid phosphatase) and antioxidant enzymes (superoxide dismutase, catalase and glutathione S-transferase) were significantly higher (p<0.05) in the control groups and a decreasing trend in the same was observed with a gradual increase in the inclusion level of TPVGC in the diet of the treatment groups. However, a reverse trend was observed for acetylcholine esterase. It was inferred that dietary supplementation of thiamine and pyridoxine loaded vanillic acid-grafted chitosan enhanced the growth performance, metabolic and immune responses in the animal-model.

DHA and EPA Content and Fatty Acid Profile of 39 Food Fishes from India.

Docosahexaenoic acid (DHA) is the principal constituent of a variety of cells especially the brain neurons and retinal cells and plays important role in fetal brain development, development of motor skills, and visual acuity in infants, lipid metabolism, and cognitive support and along with eicosapentaenoic acid (EPA) it plays important role in preventing atherosclerosis, dementia, rheumatoid arthritis, Alzheimer's disease, and so forth. Being an essential nutrient, it is to be obtained through diet and therefore searching for affordable sources of these ω-3 polyunsaturated fatty acids (PUFA) is important for consumer guidance and dietary counseling. Fish is an important source of PUFA and has unique advantage that there are many food fish species available and consumers have a wide choice owing to availability and affordability. The Indian subcontinent harbors a rich fish biodiversity which markedly varies in their nutrient composition. Here we report the DHA and EPA content and fatty acid profile of 39 important food fishes (including finfishes, shellfishes, and edible molluscs from both marine water and freshwater) from India. The study showed that fishes Tenualosa ilisha, Sardinella longiceps, Nemipterus japonicus, and Anabas testudineus are rich sources of DHA and EPA. Promotion of these species as DHA rich species would enhance their utility in public health nutrition.

Micronutrient Composition of 35 Food Fishes from India and Their Significance in Human Nutrition.

The micronutrients (vitamins and minerals) are required in small amounts but are essential for health, development, and growth. Micronutrient deficiencies, which affect over two billion people around the globe, are the leading cause of many ailments including mental retardation, preventable blindness, and death during childbirth. Fish is an important dietary source of micronutrients and plays important role in human nutrition. In the present investigation, micronutrient composition of 35 food fishes (includes both finfishes and shellfishes) was investigated from varying aquatic habitats. Macrominerals (Na, K, Ca, Mg) and trace elements (Fe, Cu, Zn, Mn, Se) were determined by either atomic absorption spectroscopy (AAS) or inductively coupled plasma mass spectrometry (ICP-MS)/atomic emission spectrometry (ICP-AES). Phosphorus content was determined either spectrophotometrically or by ICP-AES. Fat-soluble vitamins (A, D, E, K) were analyzed by high-performance liquid chromatography (HPLC). The analysis showed that, in general, the marine fishes were rich in sodium and potassium; small indigenous fishes (SIFs) in calcium, iron, and manganese; coldwater fishes in selenium; and the brackishwater fishes in phosphorous. The marine fishes Sardinella longiceps and Epinephelus spp. and the SIFs were rich in all fat-soluble vitamins. All these recommendations were made according to the potential contribution (daily value %) of the species to the recommended daily allowance (RDA). Information on the micronutrients generated would enhance the utility of fish in both community and clinical nutrition.

Development of thiamine and pyridoxine loaded ferulic acid-grafted chitosan microspheres for dietary supplementation.

Therapeutic potential of water soluble vitamins has been known for long and in recent times they are being widely supplemented in processed food. Phenolic acid-grafted chitosan derivatives can serve as excellent biofunctional encapsulating materials for these vitamins. As a proof of concept, thiamine and pyridoxine loaded ferulic acid-grafted chitosan microspheres were developed. Ferulic acid was successfully grafted on chitosan by a free radical mediated reaction and the structure was confirmed by FTIR and NMR analysis. When compared to FTIR spectra of chitosan, intensity of amide I (at around 1644 cm(-1)) and amide II (at around 1549 cm(-1)) bands in spectra of ferulic acid-grafted chitosan were found increased, indicating formation of new amide linkage. Strong signals at δ = 6.3-7.9 ppm corresponding to methine protons of ferulic acid were observed in NMR spectra of ferulic acid-grafted chitosan, suggesting the successful grafting of ferulic acid onto chitosan. Grafting ratio of the derivative was 263 mg ferulic acid equivalent/g polymer. Positively charged particles (zeta potential 31 mv) of mean diameter 4.5 and 4.8 µ, corresponding to number distribution and area distribution respectively were observed. Compact microspheres with smooth surfaces and no apparent cracks or pores were observed under scanning electron microscope. Efficient microencapsulation was further proved by X-ray diffraction patterns and thermal analysis. Preliminary anti-inflammatory activity of the vitamin-loaded microspheres was demonstrated.

Antiaging effect of dietary chitosan supplementation on glutathione-dependent antioxidant system in young and aged rats.

Aging has been defined as the changes that occur in living organisms with the passage of time that lead to functional impairment and ultimately to death. Free radical-induced oxidative damage has long been thought to be the most important consequence of the aging process. In the present study, an attempt has been made to study the salubrious effects of dietary supplementation of chitosan on glutathione-dependent antioxidant defense system in young and aged rats. The dietary supplementation of chitosan significantly reduced the age-associated dyslipidemic abnormalities noted in the levels of total cholesterol, HDL-cholesterol, and LDL-cholesterol in plasma and heart tissue. Its administration significantly (P < 0.05) attenuated the oxidative stress in the heart tissue of aged rats through the counteraction of free radical formation by maintaining the enzymatic [glutathione peroxidase (GPx) and glutathione reductase (GR)] and non-enzymatic [reduced glutathione (GSH)] status at levels comparable to that of normal young rats. Our results conclude that dietary intake of chitosan restores the depleted myocardial antioxidant status and suggest that it could be an effective therapeutic agent in treatment of age-associated disorders where hypercholesterolemia and oxidative stress are the major causative factors.

Effect of tetracycline on pancreas and liver function of adult male albino rats.

The effect of tetracycline, at two doses of 50 and 200 mg kg(-1) daily, was studied on pancreatic and liver tissue function for 14 and 21 days in adult male albino rats. For pancreatic function the parameters studied were content of amylase and lipase in pancreas, serum amylase and lipase, serum glucose and faecal fat excretion. For liver function, liver specific enzymes in serum, namely alanine amino transaminase, aspartate amino transaminase and lactate dehydrogenase were estimated. In addition, total lipid, antiperoxidative enzymes and lipid peroxidation were measured in pancreas and liver. The content of amylase and lipase in pancreas showed a small but significant decrease in the rats given 50 mg kg(-1) for 21 days and the decrease was much more significant in those receiving the 200 mg kg(-1) dose. In pancreas free radical levels show a significant increase and reduced glutathione shows a substantial decrease at the 50 mg kg(-1) level and a significant change in these parameters was observed at the 200 mg kg(-1) dose. Antioxidant enzymes, superoxide dismutase, glutathione peroxidase, glutathione reductase and catalase, showed a small but significant decrease in the pancreas of the rats treated with 50 mg kg(-1) tetracycline. A significant decrease in the antioxidant enzymes level was observed at the 200 mg kg(-1) dose. In the liver, free radical levels and reduced glutathione were within the normal range at the 50 mg kg(-1) level and significant changes were observed at 200 mg kg(-1). The antioxidant status was unaffected in liver after treatment with tetracycline at the 50 mg kg(-1) level and a significant decrease was observed at the higher dose. Our results reveal the safe nature of tetracycline with respect to the liver at the lower dose tested, whereas, both the higher and lower doses seem to have detrimental effect on the pancreas as revealed by the rise in free radical levels and decrease in the antioxidant enzyme levels.