EXTRACTION YIELD OF SOLUBLE PROTEIN AND MICROSTRUCTURE OF SOYBEAN AFFECTED BY MICROWAVE HEATING

A laboratory‐scale microwave (MW)‐assisted extraction system was constructed and compared with a conventional shaking water bath regarding the extraction of soluble proteins in soybeans. Dynamic reaction was monitored by response surface methodology in the MW‐assisted extraction system. The yield of soluble protein increased until either temperature (T) or water/solid (W/S) ratio reached an optimum point (60.1C, 12.6 mL/g), and then decreased with further increase of T or W/S ratio. In addition, the yield of soluble protein increased with time within a range of 30 min, and no critical point was observed. The molecular mass of soluble protein was distributed from 19.3 to 81.3 kDa estimated by sodium dodecyl sulfate–polyacrylamide gel electrophoresis. Scanning electron microscopy showed the destruction of the microstructure of soybean cells, which increased the extraction of soluble soy protein.     

Effect of production environment, genotype and process on the mineral content of native bitter potato cultivars converted into white chuño

BACKGROUND: Variables and interaction effects affecting the mineral concentration of Andean bitter potatoes converted into so‐called white chuño are unknown. We report on the effect of three contrasting production environments (E) on the dry matter (DM), zinc, iron, calcium, potassium, magnesium, phosphorus and sodium concentration of four potato native bitter genotypes (G) processed (P) into two different ‘types’ of white chuño. RESULTS: The DM content and iron, calcium, magnesium and sodium concentration of white chuño are significantly dependent on E, G, P, and E × G × P interaction (predominantly at P < 0.01). In particular, the DM content and calcium concentration are influenced by all variables and possible interaction effects. The zinc and potassium concentration are not significantly dependent on E × G, G × P or E × G × P interaction effects, while the phosphorus concentration is not significantly affected by the G × P or E × G × P interaction effect. Zinc, phosphorus and magnesium concentrations decrease in the ranges of 48.3–81.5%, 61.2–73.0% and 62.0–89.7% respectively. The decrease in potassium is particularly severe, with 122‐ to 330‐fold losses. Iron and calcium increase by 11.2–45.6% and 74.5–714.9% respectively. CONCLUSION: E, G, P, and various interaction effects influence the mineral concentration of traditionally processed tubers. We speculate that mineral losses are caused by leaching, while increases of iron and calcium are a likely result of absorption. Copyright © 2012 Society of Chemical Industry     

A SIMPLE AND RAPID METHOD FOR DETERMINATION OF METAL IONS IN DEVELOPING BARLEY SEEDS

A simple, rapid and accurate procedure involving flame—and flameless—atomic absorption spectroscopy was devised for the extraction and assay of major and trace metal ions in developing embryos and endosperms of barley seeds. Both embryo (maximum dry weight 20 mg) and endosperm (maximum dry weight 300 mg) samples were decomposed by digestion with nitric acid to yield a clear solution from which all the elements were analysed. Potassium, magnesium, calcium, iron, manganese and copper were determined from the embryo digests. Similarly, potassium, magnesium, calcium and manganese were determined from the endosperm digests. The validity of the procedure was confirmed by high recoveries of added metal ions. The sensitivity of analysis was such that sample size was in the range 1–12 mg.     

钠盐替代物对西式火腿品质的影响

通过肉汤模拟得出西式火腿中各替代盐的最大添加比例,并根据比例制作对照组、低钠盐组、氯化钾组、氯化钙组、乳酸钾组西式火腿,研究不同替代盐对西式火腿品质的影响。结果表明：通过模拟肉汤的感官评价,确定各替代盐的最适添加比例分别为氯化钾30%、氯化钙25%、乳酸钾35%;不同替代盐会对西式火腿的水分含量、汁液流失、质构及感官评分等造成显著差异（P＜0.05）,但并不会造成明显的色泽变化;其中低钠盐组西式火腿的综合品质最差,具体表现为水分含量最低（59.8%）、硬度最高（3 704 g）及口感得分最低（7.8 分）等,而乳酸钾相比低盐钠组品质仅有略微提升;氯化钾组和对照组西式火腿品质最为相似,感官评分、水分含量及质构等均无显著差异;氯化钙组西式火腿品质最好,表现为蒸煮损失最低（6.51%）及感官得分最高（9.1 分）等。因此,从最大钠盐替代量方面考虑,30%氯化钾组最为适合,而从提升西式火腿品质方面考虑,25%氯化钙组更为适合。     

Macroelements content of Common Pacific squid (Loligo opalescens).

The macroelement (sodium, potassium, calcium and magnesium) concentrations have been determined in various tissues of the Common Pacific squid, Loligo opalescens. The method of measurement was flame atomic emission (sodium and potassium) and absorption (calcium and magnesium) spectrometry. Edible tissues such as the tube (mantle), arms and crown, and fin contained: from 3.3 +/- 0.4 to 3.9 +/- 1.5 (1.9-6.8) g/kg wet weight of sodium; from 5.3 +/- 0.6 to 6.3 +/- 2.7 (3.3-14) g/kg of potassium; 38 +/- 7 to 100 +/- 34 (28-200) mg/kg of calcium; and from 510 +/- 100 to 950 +/- 280 (340-1500) mg/kg of magnesium. The other tissues or organs examined frequently contained a higher concentration of macroelements than the edible flesh. Statistically significant correlations between the body weight of squid and macroelement concentrations or between some pairs of metals in whole squid, mantle and hepatopancreas have been observed.     

RETENTION OF IODINE IN FORTIFIED PARBOILED RICE AND ITS PASTING CHARACTERISTICS DURING STORAGE

Iodine fortification, as potassium iodide (KI) or potassium iodate (KIO₃), in parboiled milled rice was investigated. The fortified parboiled milled rice (9–10% moisture content) contained 11.6 × 10^?2 mol KI per 100‐g salt or 9 × 10^?2 mol KIO₃ per 100‐g salt. The iodine‐fortified parboiled milled rice after dialysis retained 80.50–84.87% iodine, while the milled rice retained 97–100% iodine in the samples. Test on in vitro starch digestion showed that most iodine was released within 15 min of starch digestion. The iodine‐fortified and nonfortified parboiled milled rice showed significant higher pasting temperature, peak time and setback viscosity than normal milled rice. After storage for 5 months, iodine content in fortified parboiled milled rice decreased significantly (P ≤ 0.01), while iodine content in milled rice did not change during storage. For the rice stored at ambient temperature, the rapid visco‐analyzer amylograph viscosity (peak viscosity, trough viscosity and final viscosity) increased during the first 2 months and decreased during storage. Iodine did not affect these attributes of parboiled milled rice.     

Protein,Fiber, and Mineral Nutrition of Growing Dairy Goats

Seven yearling Alpine does were in a series of balance trials to determine apparent utilization of fiber, protein, and minerals. The 34 kg does consumed 2.2% body weight of a hay-concentrate ration that was 18.8% crude protein, 40.9% neutral detergent fiber, 24.7% acid detergent fiber, 1.18% calcium, .67% phosphorus, .39% magnesium, .98% potassium, and .48% sodium. Digestion coefficients were 59.5, 68.5, 42.3, 70.6, and 29.3 for dry matter, crude protein, neutral detergent fiber, hemicellulose, and acid detergent fiber. Retention (g/day) was: 2.6, 1.3, 2.1, 1.8, and 1.1 for calcium, phosphorus, potassium, sodium, and magnesium. Nitrogen intake was related in a positive linear fashion to fecal nitrogen, urinary nitrogen, and absorbed nitrogen. Apparent absorption rates were 2.7, 1.4, 1.3, 5.1, and 3.2 g per doe per day for calcium, phosphorus, magnesium, potassium, and sodium. Mineral retentions as percent of grams apparently absorbed were 96.2, 88.2, 80.9, 37.7, and 56.0.     

NUTRIENT COMPOSITION OF MANGO (MANGNIFERA INDICA) SEED KERNEL FROM NIGERIA

Mango (Magnifera indica) seed kernel from Nigeria were analyzed for proximate composition, inorganic ions, amino acid composition, tannin and fatty acid composition. Mango seed kernel had 44.4% moisture content, 6.0% protein, 12.8% fat, 32.8% carbohydrate, 2.0% crude fiber, 2.0% ash and 0.39% tannin. Mango kernel fat contained high amounts of stearic (46.3%) and oleic (40.0%), while palmitic, linoleic, arachidonic and behenic acids were present in small quantities (<6.6%). Of the inorganic ions detected, potassium (365 mg/100 g), phosphorus (140 mg/100 g), magnesium (100 mg/100 g) and calcium (49 mg/100 g) were present in high levels, while iron, sodium, manganese and zinc were present in small levels (< 11.0 mg/100 g). The mango seed kernel is potentially a good source of nutrients for human and animal feed.     

VARIATION AND RELATIONSHIPS AMONG SOME NUTRITIONAL TRAITS IN SICILIAN GENOTYPES OF CHICKPEA (CICER ARIETINUM L.)

The chemical composition of several chickpeas originating from Sicily, compared with the International Center for Agricultural Research in the Dry Areas genotype “ILC 484” and the Italian cultivar “Calia,” was determined. A large variability was ascertained for crude fiber (coefficient of variation [CV] = 29.3%), calcium (CV = 39.3%) and tannins (CV = 120.0%). The genotype statistically affected all nutrient characteristics assessed, whose mean values were: (1) 100‐seed weight 34.0 ± 3.3 g; (2) crude fiber 2.88 ± 0.8 g/100 g; (3) fat 6.0 ± 0.9 g/100 g; (4) total carbohydrates 62.0 ± 1.4 g/100 g; (5) ash 2.64 ± 0.2 g/100 g; (6) iron 4.50 ± 0.3 mg/100 g; (7) calcium 109.6 ± 43.1 mg/100 g; (8) magnesium 189.4 ± 18.5 mg/100 g; (9) potassium 1318.7 ± 95.6 mg/100 g; and (10) tannins 0.90 ± 1.1 g/100 g. An average energy value of 379.8 ± 6.2 kcal/100 g was computed. The wide variability ascertained for some chemical attributes such as crude fiber, tannins and Ca content, and interesting correlations observed among characteristics, such as the negative correlation between Fe and tannins or fiber, or the positive correlation between ash and Fe, suggest the possibility of identifying genotypes to be used in breeding programs for the improvement of chickpea quality in Sicily.     

Essential Elements and Cadmium and Lead in Fresh, Canned, and Frozen Green Beans (Phaseolus vulgaris L.)

Sixteen essential elements, cadmium and lead were determined in fresh, canned, and frozen green beans (Phaseolus vulgaris L.). Samples were taken during processing to determine where changes in element content occurred. Canned green beans contained lower concentrations of calcium, copper, iron, magnesium, manganese, phosphorus, potassium, and zinc, but had higher amounts of chloride, nickel, and sodium than fresh beans. No change in silicon was observed. Iron, phosphorus and potassium were lower in frozen than in fresh green beans, but calcium, sodium and zinc were higher. There was no change in chloride, copper, magnesium, manganese and silicon due to freezing. Element retention ranged from 51 - 100% for canned and from 73 - 171% for frozen green beans.     

ISOLATION AND CHARACTERIZATION OF TRYPSIN INHIBITORS FROM SOME THAI LEGUME SEEDS

Trypsin inhibitors from cultivars of cowpea (Vigna unguiculata (L.) Wasp.), pigeon pea (Cajanus cajan (L.) Millsp.) and bambara groundnuts (Voandzeia subterranea (L.) Thou) grown in Thailand were isolated and characterized. Extraction of seeds with NaCl rendered a higher recovery of trypsin inhibitor than other solvents tested (P<0.05). The extraction time affected the inhibitor recovery (P<0.05). The extraction time of 3 h was optimum for the recovery of trypsin inhibitor from pigeon and bambara groundnuts, whereas 1 h was optimum for cowpea. Based cn inhibitor activity of zones separated by electrophoresis, the molecular mass of the inhibitor from bambara groundnuts was 13 kDa. Two inhibitory bands were observed for cowpea (10 and 18 kDa) and pigeon pea (15 and 25 kDa). Partial purification of inhibitors was achieved by heat‐treatment at 90C for 10 min, followed by ammonium sulfate precipitation with 30–65% saturation. The partially purified inhibitors from four seeds were heat stable up to 30 min at 90C at pH 7.0. The activities were also retained over a wide pH range at 25C but were lost when samples were treated with β‐mercaptoethanol prior to electrophoresis.     

Mineral contents and distribution between the soluble and the micellar phases in calcium‐enriched UHT milks

A study concerning the content of mineral elements (calcium, magnesium, sodium, potassium and phosphorus) and the distribution between the soluble and the micellar phases has been carried out on mineral—mainly calcium—enriched UHT milks. Total calcium contents were 1371–1793 mg l^?1 in the 10 brands examined. Percentages of calcium in the soluble phase varied from 23.6 to 37.2%, whereas ionic calcium concentrations found were within a very wide range (44–91 mg l^?1). The different forms of phosphorus were studied by ³¹P‐NMR. Spectra indicated that the majority of the brands employed polyphosphates as stabilizers. Ingredients used to fortify these products consisted of dairy fractions and calcium salts. The modifications in salt balance as consequence of these practices are discussed. Copyright © 2004 Society of Chemical Industry     

Composition and calcium status of acid whey from pasteurized,UHT‐treated and in‐bottle sterilized milks

Whey extracts were obtained from pasteurized, UHT‐treated and in‐bottle sterilized milks. After acidic precipitation of casein the concentration of protein, NPN, lactose, lipid, calcium, magnesium and potassium was determined. Among the parameters examined, protein content was significantly reduced in the whey extracts from UHT‐treated and in‐bottle sterilized milks compared with that from pasteurized milk, while lactose content was increased. Calcium extracted in whey was at least 80% of total calcium of the milk. The total calcium to protein ratio of whey was increased as a function of the thermal treatment of milk, while ionic calcium was about 50% of total calcium in all whey extracts. In vitro protein digestibility was found to be significantly lower in whey from UHT‐treated and in‐bottle sterilized milks than in that from pasteurized milk. Parallel estimation of the percentage of ionic calcium and of the solubility of proteins in the pH range 2–10 indicated that calcium was not involved in the pH‐dependent solubility of proteins extracted in the whey, the extent of solubility being essentially a function of the thermal treatment of milk. The results suggest that calcium was not responsible for the formation of soluble protein macroaggregates with impaired digestibility that are present in whey from milk subjected to heat treatment of increasing intensity.     

PURIFICATION AND CHARACTERIZATION OF TRYPSIN FROM PYLORIC CAECA OF BIGEYE SNAPPER (PRICANTHUS MACRACANTHUS)

Trypsin from the pyloric caeca of bigeye snapper was purified and characterized. Trypsin had an apparent molecular weight of 23.8 kDa when analyzed using sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS‐PAGE) and substrate‐gel electrophoresis. The trypsin fraction consisted of three isoforms as evidenced by the appearance of three different bands on native‐PAGE. Optimal activity was observed at 55C and pH range of 8–11. The activity of trypsin fraction was completely inhibited by soybean trypsin inhibitor and was partially inhibited by E‐64 and ethylenediaminetetraacetic acid. CaCl₂ partially protected the trypsin fraction from activity loss at 40C, while NaCl (0–20%) decreased the activity in a concentration‐dependent manner. The apparent Michaelis–Menten constant (K_m) and catalytic constant (k_cat) were 0.312 mM and 1.06 s, respectively when Nα‐Benzoyl‐dl ‐arginine ρ‐nitroanilide was used as a substrate. Trypsin from the pyloric caeca of bigeye snapper generally showed similar characteristics to other fish trypsins.     

Movement and absorption of major minerals and water in ovine gastrointestinal tract

Movement of calcium, chloride, magnesium, potassium, sodium, and water in the intestine of sheep was determined with cerium-141 as an unabsorbed reference substance. Net secretion of phosphorus and sodium, but not of potassium and calcium, was observed to the rumen. Water disappeared from the omasum and was secreted in the abomasum. Chloride secretion occurred in the omasum and more in the abomasum. Extensive secretion in the duodenum increased flows of sodium and potassium 8 to 9 times; of calcium, chloride, and phosphorus 3 to 6 times; of magnesium 1.3 times; and of water 12 times. Reabsorption was rapid in the small intestine, the major site of disappearance of all ions. Rates of disappearance decreased with increasing distance from the pylorus. Little further net disappearance of calcium, phosphorus, magnesium, or potassium was found in the large intestine, whereas water, sodium, and chloride disappearance continued. Overall absorption of sodium, potassium, and chloride was approximately 90%, of phosphorus 63%, of calcium 38%, and of magnesium 71%. This study highlights the importance of endogenous secretions in mineral absorption in the sheep.     

Variation in the Vitamin and Mineral Content of Raw and Cooked Commercial Phaseolus Vulgaris Classes

Raw and cooked samples of nine different commercial classes of the Phaseolus vulgaris L. species were analyzed for their contents of five water-soluble vitamins and nine minerals. On a 100g dry weight basis, the mean vitamin and mineral values of the raw bean samples amounted to the following: thiamin 0.99 mg, riboflavin 0.20 mg, niacin 1.99 mg, vitamin B₆ 0.49 mg, folic acid 0.30 mg, phosphorus 0.46g, sodium 10.3 mg, potassium 1.54g, calcium 0.15g, magnesium 0.20g, zinc 3.2 mg, manganese 1.4 mg, copper 0.91 mg, and iron 5.84 mg. With a few exceptions variabilities of these nutrients between bean classes exceeded those within classes. Nutrient variabilities in cooked samples, again with a few exceptions, were higher than in the corresponding uncooked material. Retention values of water-soluble vitamins during cooking between bean classes averaged between 70 and 75%. Retention of minerals during cooking ranged from a low of 38.5% for sodium to total retention for calcium, with the majority of the minerals falling into the 80–90% level.     

CHEMICAL COMPOSITION AND NUTRITIONAL POTENTIAL OF VIGNA UNGUICULATA SSP. CYLINDRICA (FABACEAE)

Seeds of Vigna unguiculata (L.) Walp. ssp. cylindrica (L.) Estt. (Fabaceae) were analyzed for proximate composition, proteins, fatty acids, minerals, antinutritional factors and phytohaemagglutinating activity. Crude protein, crude fat, ash and nitrogen free extractives constitute 29, 10, 4 and 53%, respectively. The caloric value of 100 g dry matter of seed material was 1737 KJ. The essential amino acids, isoleucine, lysine and tyrosine+phenylalanine are present in higher concentrations as 124.3, 79.5 and 79.1 mg/100 g crude protein, respectively. The unsaturated fatty acids constituted more than 60% of total fatty acids. The seeds were found to be a potential source of minerals such as potassium, calcium, phosphorus, zinc and iron. The antinutritional factors such as total free phenols, tannins, L‐DOPA, hydrogen cyanide and phytic acid contents were determined. The effect of cooking on the levels of nutritional and antinutritional factors was also assayed. Cooking caused reduction of 0.02, 0.59 and 0.36% in the mineral constituents of potassium, calcium and phosphorus, respectively. More than 70% of the antinutritional factors were eliminated and there was an increase of crude fiber content.     

PURIFICATION AND CHARACTERIZATION OF A CATALASE FROM THE LIVER OF BULLFROG, RANA CATESBEIANA SHAW

A catalase was purified from the liver of bullfrog, Rana catesbeiana Shaw, after extraction, ammonium sulfate precipitations, DEAE‐Sephadex A‐50 chromatography, gel filtration chromatography on a Sephadex G‐150 column, ion exchange chromatography on a DEAE‐Sephacel column and Sephacryl S‐300 column. The yield and purification from the starting crude extract were 0.25% and 73.57‐fold, respectively. The purified catalase with an apparent molecular mass of 186 kDa was shown to be composed of four identical subunits of apparent molecular mass of 47.7 kDa. The purified catalase is active over a broad pH range of 6.0–10.0, and it has an isoelectric point of 6.3. The enzyme showed a K_mfor H₂O₂of 20 mM and an apparent V_maxof 51.91 U/mg, and its maximum absorption was at 408 nm in the visible portion of the spectrum. In addition, the purified enzyme was markedly inhibited by azide, cyanide and hydroxylamine.     

Effect of biopolymers containing natamycin against Aspergillus niger and Penicillium roquefortii on fresh kashar cheese

Fungal spoilage during refrigerated storage is one of the main safety and quality‐related problems for dairy products. The effect of wheat gluten (WG) and methyl cellulose (MC) biopolymers containing natamycin (NA) on the growth of Aspergillus niger and Penicillium roquefortii on the surface of fresh kashar cheese during storage at 10 °C for 30 days was investigated. Wrapping of A. niger‐inoculated cheese with MC films containing 5–20 mg NA per 10 g resulted in approximately 2‐log reductions in spore count. Two mg NA per 10 g included into WG films was sufficient to eliminate A. niger on the surface of cheese. However, MC and WG films containing NA did not cause any significant decrease in P. roquefortii count on the cheese surface. Therefore, especially use WG films in dairy applications could be an effective way of controlling A. niger growth on these products.