Impact of maturity on the physicochemical and biochemical properties of chinook salmon roe

Various physicochemical and biochemical properties were compared between raw mature and immature chinook salmon (Oncorhynchus tshawytscha) roe. The pH, osmolality and moisture content were lower for mature salmon roe but egg size, viscosity, protein, crude lipid and ash content values were all higher. Maturity had an impact on the profile of amino acids but not on fatty acids. Maturity affected mineral and trace elements with higher Ca, Co, Mg, P, S and lower Cu, Fe, Mn, Na, Zn found in mature salmon roe. Immature roes had more α- and total tocopherols but less γ- and δ-tocopherols. Soluble proteins from mature and immature roes were similar, but the profiles of membrane-bound proteins differed. Thus maturity will affect functional and physical properties during processing and consumption of chinook roes.     

Monitoring volatile and nonvolatile amines in dried and salted roes of tuna (Thunnus thynnus L.) during manufacture and storage

Dried and salted roe, obtained from the reproductive organs of female tuna (Thunnus tynnus L.), is a typical fish-based food in the Mediterranean area of Spain. In the present study, we monitored the formation of volatile amines (trimethyamine nitrogen [TMA-N] and total basic volatile nitrogen [TBVN]) and nonvolatile amines (biogenic amines) in dried and salted tuna roe after processing and storage for 8 weeks at 4, 20, and 30 degrees C. The salting and drying process significantly increased the TBVN, cadaverine, tyramine, phenylethylamine, and tryptamine contents, and bacteria with histamine decarboxylase activity were detected both in raw and in dried and salted tuna roes. During storage of tuna roe, TMA-N and TBVN levels increased significantly after the fourth week of storage at 30 degrees C, whereas biogenic amine contents remained more or less constant. However, samples stored at 30 degrees C showed histamine formation after the first week of storage, with a concentration of < 50 ppm. The volatile and nonvolatile amine concentrations in tuna roe were below the consumer safety limit, with the exception of the total biogenic amine level in roe stored at 30 degrees C, which exceeded the European Community's recommended limit (300 ppm). These results indicate that in properly stored tuna roe, histamine formation will not represent a serious health risk to consumers unless the tuna roe has previously been mishandled.     

Chemical compositions of the roes from skipjack,tongol and bonito

Chemical compositions of roes from three tuna species including skipjack (Katsuwonous pelamis) (SJK), tongol (Thunnus tonggol) (TGL) and bonito (Euthynnus affinis) (BNO) were determined. Tuna roes contained 72.17–73.03% moisture, 18.16–20.15% protein, 3.29–5.68% lipid and 1.79–2.10% ash. Non-defatted and defatted roes from all species contained protein with a molecular weight of 97 kDa as the major component. Glutamic acid and glutamine were the most abundant amino acids (12.18–12.65 g/100 g protein), while K, Na and P were the major elements in defatted-tuna roes. Crude lipids from tuna roes contained phospholipids as the major component (51.22–54.90% of total lipids) with high content of docosahexaenoic acid (C22:6 n-3) (20.53–26.19% of total lipids). Cholesterol contents of crude lipids from the roes of SJK, TGL and BNO were 172, 122 and 94 mg/100 g lipids, respectively. Therefore, tuna roe could be a promising source of valuable nutrients for human food and animal feeds.     

Comparison of mineral and trace element contents in onion cultivars (Allium cepa L.)

BACKGROUND: P, Na, K, Ca, Mg, Fe, Cu, Zn, Mn and Se were determined in five traditional onion cultivars (Allium cepa L.) from Tenerife (Guayonje, San Juan de la Rambla, Carrizal Alto, Carrizal Bajo and Masca) and a commercial cultivar (Texas Early Grano 502) grown under the same agronomic, soil and climatic conditions in order to find out differences between these cultivars. RESULTS: Carrizal Alto presented the highest K content and lowest P, Na, Fe, Zn, Mn and Se. Texas cultivar had the highest P, Mg and Se contents, and the lowest contents of Ca, Cu and Mn. There were clear differences in the mineral and trace elements contents between the two seed origins of San Juan de la Rambla cultivar. Many correlations were found between the parameters analyzed, emphasizing the Fe? Zn and Ca? Mn correlations. CONCLUSION: There were differences in the mineral and trace element composition between the onion cultivars. The environment and agronomic practices could affect the genetic information of the seeds, determining changes in the mineral and trace element composition. Linear discriminant analysis is a useful tool for differentiating onion samples according to cultivar and seed origin. Copyright © 2008 Society of Chemical Industry     

Influence of Cape gooseberry (Physalis peruviana L.) addition on the chemical and sensory characteristics and mineral concentrations of ice cream

In this research, the influence of Cape gooseberry (CG) addition at different concentrations (5, 10 and 15%) on the physical, chemical and sensory properties and mineral contents of ice cream was investigated. The increment of CG concentration caused the decrease of fat, protein, pH and overrun values in ice cream, on the contrary it increased the total solid, ash, titratable acidity, viscosity values and first dripping and complete melting times. S contents of ice creams significantly increased with the CG addition. Moreover, CG increased K, and Na concentrations of ice cream, while lowered Ca and P contents. Mg contents of ice creams didn't change with CG addition (P > 0.05). Fe, Zn, Mn and Ni were determined as minor elements in ice cream samples and a significant increase was observed in Fe, Zn and Mn values (P < 0.05). The addition of CG did not affect Ni content of ice creams. The sensory results indicated that the ice cream containing 15% CG was the highest-scored by the panelists.     

Lipid components and water soluble metabolites in salted and dried tuna (Thunnus thynnus L.) roes

The salted and dried product of tuna roe (bottarga) is a seafood characteristic of the Mediterranean area and exported all over the world. Samples of bottarga from bluefin tunas (Thunnus thynnus, L.) caught in the southwest Mediterranean sea were analysed. The samples were characterised by high content of marine wax esters (55–67 mol% of lipid classes), of docosahexaenoic (22:6 n-3, 25 w%) and oleic (18:1 n-9, 19 w%) fatty acids. Cholesterol was detected as 7–9 w% of lipids. Free fatty acids, index of lipid hydrolysis, represented 32–39 mol% over total fatty acids. Among metabolites, nutrients as taurine, nicotinamide and β-alanine, were found. The microflora comprised staphylococci, enterococci (2.2 log₁₀ CFU/g) and lactic acid bacteria (3 log₁₀ CFU/g). The food-borne pathogens Staphylococcus aureus, Listeria monocytogenes and Salmonella spp. were not detected. These findings indicate tuna bottarga as valuable source of nutrients.     

The nutrients of exotic mushrooms (Lentinula edodes and Pleurotus species) and an estimated approach to the volatile compounds

Texture, nutritive values and volatile compounds of Lentinula edodes, Pleurotus ostraetus and Pleroutus sajor-caju mushrooms were determined. The volatiles have been found out with an estimation approach by carrying out gas chromatography and mass spectrophotometer (GS–MS) Library Catalogue comparison. Neither regular increase nor decreases were observed for the values of texture, moisture, ash and protein values of L. eddoes. While a decrease, negative correlation was seen in values of vitamin C, folic acid and niacin values from the first flush to fourth flush periods, there was no correlation in the values of riboflavin and thiamin. Average mineral values of Shiitake (mg/kg wet basis) were: Zn, 10.18; Fe, 5.69; P, 998.47; Ca, 64.55; Mg, 191.89; K, 2347.33; Na, 622.40, proximate composition, vitamin C, folic acid, niacin, B1, B2 were determined in Pleurotus mushrooms. These mushrooms can contribute nutrition for protein and vitamin daily requirements. The mean mineral values of Pleroutus species (mg/kg, wb) were: Zn, 11.18–9.31; Fe, 14.80–7.94; P, 998.47–716.31; Ca, 81.16–23.66; K, 2225.00–2687.00; Na, 750.77–773.67, respectively. The volatile compounds, typical esters which are found in the mushrooms, hydrocarbons and fatty acids derivatives were determined with estimated approach by comparing library catalog of (GS–MS).     

Geometric Characteristics and Chemical Composition of Okra (Hibiscus esculentus L.) Grown Under Semi-arid Conditions

Abstract

A Landrace and seven foreign genotypes of okra (Hibiscus esculentus L.) were grown in a randomized complete block design at Jordan University of Science and Technology (JUST) Experimental Station in northern Jordan during the 1997 and 1998 growing seasons. The pods were studied for their physical properties, chemical composition, and mineral content. Geometric characteristics of okra fruits were significantly influenced by genotypes. Mosel and Steen had higher protein content than the Landrace, being 23.19, 22.43, and 19.96% respectively. The average fruit mass of different genotypes showed a trend similar to that found in fruit volume; Vigorpak had the highest fruit mass and volume, whereas Mosel had the lowest. Number of pods per plant showed very wide range for all genotypes, which ranged between 17 and 31. Data demonstrated that the variability within individual okra genotypes may be was due to environmental effects. High variability was observed in chemical composition among different genotypes. However, the genotype having high carbohydrate content showed low fiber content. All mineral contents (Ca, Na, Cu, Mn, Zn, Mg, P, and K) varied significantly among the genotypes except for Fe content, which showed no significant differences between genotypes. Mosel genotype was found superior in its mineral contents, whereas other genotypes might be considered good source for proteins, fiber, carbohydrate and minerals. The investigated genotypes seem to be a good source of minerals for human diet. The variation in mineral contents is probably due to genotype, environment and/or genotype environment interaction.     

Comparative study of the mineral composition of several varieties of potatoes (Solanum tuberosum L.) from different countries cultivated in Canary Islands (Spain)

Potatoes are a basic component of human diets worldwide being an excellent source of minerals linked the maintenance of health. Contents of calcium (Ca), magnesium (Mg), potassium (K), sodium (Na), cupper (Cu), iron (Fe), manganese (Mn), zinc (Zn), nickel (Ni) and chromium (Cr) in seventy‐four fresh potato samples from different varieties consumed in Tenerife Island (Canary Islands, Spain) were determined by flame atomic absorption spetrometry (FAAS). The mean concentrations were 60.1 mg kg^?1, 222 mg kg^?1, 5047 mg kg^?1, 125 mg kg^?1, 1.69 mg kg^?1, 8 mg kg^?1, 1.70 mg kg^?1, 3.88 mg kg^?1, 62.7 μg kg^?1 and 19.9 μg kg^?1 for Ca, Mg, K, Na, Cu, Fe, Mn, Zn, Ni and Cr, respectively. The varieties of local potatoes presented higher mineral contents than imported potatoes. Potassium presented the highest contents in all varieties of potatoes. Iron was the most abundant microelement. Local potatoes offer greater nutritional contributions to the recommended intakes than imported varieties. Within the macrominerals, the highest contribution to the intakes was observed for K, while Fe was the trace element with the largest contribution to the proposed intake.     

Mineral composition in four varieties of avocado (Persea gratissima, L.) from the island of Tenerife

The contents of macroelements (Na, K, Ca, Mg, and P) and microelements (Fe, Cu, Zn, Mn, and B) of four varieties of avocado obtained and consumed in the island of Tenerife, Canary Islands, have been determined. The samples mineral contents of the different avocado varieties showed significant differences. Thus, the concentration levels of Ca, Mg, and Mn are higher in the Hass variety; those of K, Fe, and Zn, in the Orotava variety; those of Na and B in the Hass and Fuerte varieties; that of P in the Arona and Hass varieties; and that of Cu in the Arona and Fuerte varieties. The area of origin of Hass avocado also influences the mineral content of the samples: those from the north of Tenerife show higher contents of K, Ca, P, Fe, Cu, Zn, and B, and those from the south, of Na, Mg, and Mn.     

Physico-chemical, amino acid composition, functional and antioxidant properties of roe protein concentrates obtained from Channa striatus and Lates calcarifer

Roe protein concentrates prepared from Channa striatus (CRPC) and Lates calcarifer (LRPC) were investigated for physico-chemical characteristics, amino acid composition, functional properties and antioxidant activity. Channa and Lates roes yielded 20.7% and 22.5% of protein concentrates possessing 90.2% and 82.5% protein, respectively. Major differences were not observed in each of the amino acids except leucine in CRPC and LRPC. The solubility of protein was 3.93-54.6% and 1.6-55.5% over a pH range of 2-12 in CRPC and LRPC, respectively. Water absorption, oil absorption, foam capacity, stability and emulsifying capacity were found to be higher in CRPC than in LRPC. Antioxidant activity determined by the radical scavenging activity and ferric reducing power was higher in CRPC. SDS-PAGE of both roe protein concentrates showed protein bands of 170, 95 and 55 kDa. Moisture sorption isotherms of protein concentrates indicated their hygroscopic nature.     

Genotypic variation of mineral elements contents in rice (<Emphasis Type="Italic">Oryza sativa</Emphasis> L.)

Mineral nutrition of potassium (K), calcium (Ca), sodium (Na), magnesium (Mg), iron (Fe), zinc (Zn), copper (Cu) and manganese (Mn) are important for human health. The method of inductively coupled plasma mass spectrometry (ICP-MS) was employed to determinate the contents of K, Ca, Na, Mg, Fe, Zn, Cu and Mn in milled rice (Oryza sativa L.) of 274 rice genotypes. The results showed that the visible difference could be found for the contents of eight elements in milled rice among rice genotypes studied. It existed the possibility to select the genotype(s) with abundant of mineral nutrient from the genetic resource. Meanwhile, the contents of mineral elements in brown rice were significantly higher than those in milled rice. The averages of K, Mn and Cu contents of indica rice were significantly lower than those of japonica rice, while no significant difference was found for other five element contents between indica and japonica rice genotypes. The average contents of Na and Cu in non-glutinous rice genotypes were higher than those in glutinous ones, whereas the averages of K and Mn contents in non-glutinous rice genotypes were lower in present experiment. Additionally, the K, Ca and Mg contents of milled rice from white brown rice were significantly higher than those from red brown rice, and Ca content of milled rice from white brown rice was also visibly higher than that from black brown rice. For microelements, significant difference was observed for Zn content between milled rice from red and white brown rice, or between milled rice from red and black brown rice. Some genotypes with abundant mineral nutrient in milled rice had been selected and could be used in rice nutrient breeding.     

Estimation of minerals,nitrate and nitrite contents of medicinal and aromatic plants used as spices,condiments and herbal tea

In this study, the minor and major mineral contents of 31 kinds of medicinal and aromatic plant collected from the south region of Turkey in 2004 year were established by inductively coupled plasma atomic emission spectrometry (ICP-AES). The samples were composed of Al, Ca, Fe, K, Mg, Na, P and Zn. The highest mineral concentration were measured between 57.70–2962.74 mg/kg Al, 1160.04–16452.88 mg/kg Ca, 44.83–1799.5 mg/kg Fe, 3570.73–27669.72 mg/kg K, 477.17–4313.59 mg/kg Mg, 1102.62–20912.33 mg/kg Na, 443.60–9367.80 mg/kg P and 7.18–48.36 mg/kg Zn. The highest values of Ca, K and P were established in Foeniculum vulgare (bitter fennel) (16452.88 mg/kg), Ocimum minumum (basil) (27669.72 mg/kg) and F. vulgare (bitter fennel) (9367.80 mg/kg), respectively. The heavy metal contents were determined too low in all samples.     

Chemical composition,amino acid and fatty acid contents,and mineral concentrations of European beaver (<Emphasis Type="Italic">Castor fiber</Emphasis> L.) meat

The present investigation was designed to determine the meat nutritional profile of European beaver (Castor fiber L.). The proximate composition, energy value, amino acids composition, chemical scores for indispensable amino acids, fatty acids composition and mineral concentrations were determined. In 100 g of meat the content for moisture ranged from 75.42 to 77.32 g, for protein from 20.21 to 22.33 g, for fat from 0.66 to 2.44 and for ash from 1.12 to 1.24 g. The Nutritional Quality Index for muscle protein was 9. The indispensable amino acids (IAA) at the highest content were lysine and leucine (1.85 and 1.65 g 100 g^?1). The average percentage of IAA was 45% and their chemical scores amounted to more than 100. The total percentages of trans-, saturated (SFA), mono, and polyunsaturated (PUFA) fatty acids were 2.25, 32.25, 18.83 and 49.08%. The ratio of PUFA/SFA and n-6/n-3 PUFA were 1.56 and 5.58. The cholesterol content averaged 55.10 mg 100 g^?1. The muscle tissue of beavers contained favourable amount of minerals, particularly Fe and heme Fe (64.49 and 45.60 mg kg^?1), Zn and Cu (45.07 and 0.98 mg kg^?1), as well a low level of Na (461.9 mg kg^?1). Summing up, beavers are a valuable nutritional meat source with a desirable chemical composition and a low calorific value and can constitute a healthy alternative food as advantageous for human health and coherent with diet recommendations.     

Essential elements and contaminants in edible tissues of European and American lobsters

In several European countries clawed lobsters, such as the European (Homarus gammarus) and American (H. americanus) ones are widely consumed. Yet, information about essential elements and contaminants in both species is still scarce. Therefore, the aim of this work was to characterise the elemental content in the edible part (muscle, hepatopancreas, gonads and roe) of both homarids and to compare them with the daily intake recommendations and maximum allowed levels. Two techniques were employed: energy-dispersive X-ray fluorescence (EDXRF) to quantify Cl, S, K, Ca, Fe, Cu, Zn, As, Se, Br and Sr; and flame atomic-absorption spectrometry (FAAS) to analyse Na, Mg, Mn, Cd, Hg and Pb. Significant differences were found in the elemental composition of edible tissues of both species, likely reflecting the distinct physiological role of those tissues: muscle (higher: Na, Mg, Ca and Sr; lower: Fe, Se, Cd); hepatopancreas (higher: Fe, Cu, Br and Cd); gonads (lower: Cl, Ca, Zn and Hg); and roe (higher: Na and Br; lower: K and As). Statistical differences in the elemental composition of each tissue were found between both homarids: Muscle (Na, Se, As and Hg); Hepatopancreas (Na, Mg, Fe, Cu, Se, Br and Hg); and gonads (S and Zn). Since the geographical distribution of both species is different, the differences likely reflect distinct elemental composition in the aquatic environment and, consequently in the feed chain. Both lobster species were rich sources of Na, Cl, Cu, Zn and Se for human consumption. Regarding contaminants, only Cd was detected at high concentrations in the hepatopancreas of both homarids. Despite Cd values were well above the maximum allowed level set by the European Commission for crustaceans’ muscle, so far any limit value was set for crustaceans’ hepatopancreas. Nonetheless, the present study recommends avoiding or moderately consuming this tissue in homarids.     

Oxidative stability of lipid components of mullet (Mugil cephalus) roe and its product “bottarga”

The lipid composition and oxidative stability of mullet (Mugilcephalus) raw roes and cured products (bottarga) from two different fishing areas have been studied and compared to find lipid modifications due to manufacturing procedures. Moreover, n-3 PUFA oxidation in raw roes and cured products was monitored during storage at −20 °C, and in grated sample of bottarga at room temperature. Oxidative degradation of n-3 PUFA was evaluated by conjugated dienes fatty acids hydroperoxides determination. The treatments on mullet roe did not affect the lipid level (fatty alcohols and acids, cholesterol) and the amount of hydroperoxides. No significant difference is observed between n-3 PUFA levels during processing and at different storage conditions. The order of oxidative stability, as calculated by the hydroperoxides determination was: grated bottarga < whole bottarga < raw roe.     

Genotypic variation and relationships between quality traits and trace elements in traditional and improved rice (Oryza sativa L.) genotypes

In this study, we assessed the extent of genotypic differences among rice genotypes for grain size, milling quality, cooking properties, protein, and the mineral contents of Fe, Zn, Mn, and Cu in unpolished rice varieties. Further, relationship among grain quality traits and mineral contents was determined. The results showed that the visible difference could be found in the mineral contents among rice genotypes studied. The contents of Fe and Zn in traditional genotypes were significantly higher than those of improved cultivars. There was a negative correlation between grain yield and mineral contents. However, Fe, Zn, Mn, and Cu contents appeared to be positively correlated. The relationships between mineral element contents and cooking quality traits viz., kernel length after cooking and kernel linear elongation ratio were positively correlated, indicated the role of micronutrients in cooking quality traits. Both Fe and Cu contents were correlated positively and significantly with head rice recovery. The eigen values of 1st 6 principal components (PC) were > 1.0. The present study suggests that breeding for high minerals will be probably realistic.     

Chemical composition of shell and flesh of three prawn samples from Lagos lagoon

The protein, ash, fibre and individual mineral ion contents of three species of prawn taken from the Lagos lagoon were determined. The median liveweights of Macrobrachium vollenhovenii (Herklots), Palaemon species A (Powell) and Penaeus notialis were respectively, 25.52 g (shell + head 16.76 g; flesh 9.26 g), 3.15 g (shell + head 1.71 g; flesh 1.44 g) and 5.11 g (shell + head 2.14 g; flesh 2.96 g). All (shell + head) samples had high protein, ash and fibre contents but only the protein content was high in the flesh, which had low or undetectable quantities of fibre. The fat and carbohydrates contents were generally low. In M vollenhovenii the (shell + head) was a better source of Mg, Zn, Cu and K than the flesh, which was a better source of Ca, Ni, P, Fe, Co and Na. In P species A the (shell + head) was a better source of Ca, Mg, P, Cu, Co, Na and K than the flesh (higher in Zn and Ni). In P notialis the (shell + head) was the better source of Ca, Zn, P, Fe and Co and the flesh the better source of Mg, Ni, Fe, Na and K. Copyright © 2004 Society of Chemical Industry     

Optimum extraction and recovery of trypsin inhibitor from yellowfin tuna (Thunnus albacores) roe and its biochemical properties

Effect of lipid removal, extraction medium and extraction time on the isolation and recovery of trypsin inhibitor from yellowfin tuna (Thunnus albacores) roe was investigated. Trypsin inhibitor extracted from defatted tuna roe showed the higher specific inhibitory activity than extracted from origin tuna roe. Optimal extraction medium was attained by shaking the defatted yellowfin tuna roe powder in 10 mm Na phosphate buffer (pH 7.0) containing 0.5 m NaCl (P < 0.05). The extraction time affected the inhibitor recovery significantly (P < 0.05). The extraction time of 30 min was optimum for recovery of trypsin inhibitor from yellowfin tuna roe. The biochemical properties of trypsin inhibitor from yellowfin tuna roes were also determined. The inhibitor was stable to heat treatment up to 60C and over a broad pH range (5‐8). Increasing the concentration of salt (up to 3%, w/v) did not significantly decrease the trypsin inhibitory activity. However, the activity decreased when trypsin inhibitor was incubated with metal ions at ambient temperature for 30 min.     

Variations of vitamin and mineral contents in raw goat milk of the indigenous Greek breed during lactation

Raw goat milk samples from the indigenous Greek breed in the area of Ioannina, northwestern Greece, were collected during one lactation and analyzed for vitamins A, E, B₁, B₂, and C and for minerals Ca, Mg, P, Na, K, Cu, Fe and Zn. Also, the major constituents of goat milk, namely fat, protein, lactose and solids-non-fat, were determined. The average composition (%) of milk was: fat 4.10, protein 3.36, lactose 4.48 and solids-non-fat 8.54. The mean concentration of the fat-soluble vitamins retinol (A) and α-tocopherol (E) were 0.013 and 0.121 mg/100 ml, respectively. The mean concentration of the water-soluble vitamins, thiamin (B₁), riboflavin (B₂) and ascorbic acid (C) were 0.260, 0.112 and 5.48 mg/100 ml, respectively. Seasonal variations were observed for all vitamins studied. Thiamin had significantly (P < 0.05) higher concentrations during summer than in winter and early spring. The observed variations of the studied vitamins might be attributed to the differences in the feeding of goats during lactation. The mean mineral contents (mg/100 g) of goat milk were Ca 132, P 97.7, Na 59.4, K 152, Mg 15.87, Cu 0.08, Fe 0.06, Zn 0.37 and Mn 6.53 μg/100 g. Seasonal variations were observed for the major minerals Ca, P, K, and the trace elements Cu and Zn.