ISOLATION AND CHARACTERIZATION OF THE PROTEIN THAT CO-PURIFIES WITH SOYBEAN (GLYCINE MAX L.) GLYCININ1

Soybean (Glycine max. L.) glycinin (11S) purified by the Thanh and Shibasaki method (J. Agric. Food Chem. 24, 1117–1121 (1976)) is usually 90% pure. One of the impurities present in such glycinin preparations is the sulfur-rich salt-soluble globulin (SRP). The SRP which co-purifies with glycinin is resolved when such glycinin preparations are chromatographed on a DEAE DE-53 anionexchange column. It represented up to 5.32% of the total protein recovered. Hydrophobic and disulfide exchange interactions are the likely forces responsible for the co-purification of SRP with glycinin.     

EFFECTS OF SODIUM DODECYL SULFATE,GUANIDINE HYDROCHLORIDE,UREA, AND HEAT ON DENATURATION OF SULFUR RICH PROTEIN IN SOYBEANS (GLYCINE MAX L.)1

Soybean sulfur‐rich protein (SRP) has a stable hydrophobic interior that is resistant to denaturation and unfolding. About half of the tryptophan residues in native SRP are inaccessible to acrylamide quenching. Maximum unfolding, as assessed by fluorescence quenching experiments, was afforded by 2 M urea, 6 M guanidine HCl and 30 nun moist heat. Sodium dodecyl sulfate (SDS) did not improve tryptophan accessibility to acrylamide quenching. SRP tryptophan residues were minimally accessible to the iodide quenching indicating a nonionic environment around the majority of the tryptophan residues in SRP.     

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.     

PRELIMINARY STUDIES ON PHYSICAL AND NUTRITIONAL QUALITIES OF SOME INDIGENOUS AND IMPORTANT RICE CULTIVARS OF NORTH‐EASTERN HILL REGION OF INDIA

ABSTRACT

The northeastern hills of India are endowed with rich source of rice germplasm, which may be safely estimated about 9,000 accessions, excluding the redundancies. Even though much of the germplasm have been collected, studies on nutritional aspects of these local cultivars are still lacking. Fifteen important indigenous rice genotypes collected from different rice growing ecosystem of this region were studied for physical and nutritional qualities. Kernel color of the genotypes varied from white to dark purple. All the genotypes except Manipuri were of bold‐grain type. Most of the genotypes studied have fat contents more than 2.0%. The protein content was found higher in Chahou angouba and Naga special. Five cultivars were identified as high‐protein cultivars of rice, with 10–12.07% protein content. Amylose content varied from 2.27 to 24.5%. Most of long‐grained genotypes recorded lesser amylose than short grained. Chahou varieties were found aromatic and glutinous, which demand higher market prices in local market.

PRACTICAL APPLICATION

The north‐eastern hills of India are endowed with rich source of rice germplasm, and much of the germplasm have been collected, but studies on basic and advanced nutritional aspects of these local cultivars are still lacking. This part of India has valuable rice genotypes of strong aroma, glutinous characters and slender grains with high amount of protein, fat and fiber. Having not known to the rest of the world and even to indigenous end users, some of such cultivars have already been lost, and some more are at the verge of extinction. Quality evaluation done in the present study provided useful information on their commercial exploitation and utilization in breeding programs of nutritional enhancement of rice to fight malnutrition among rice‐consuming population, which is largest in the world.     

PHYSICOCHEMICAL AND SENSORY CHARACTERISTICS OF SELECTED MICHIGAN SWEET CHERRY (Prunus avium L.) CULTIVARS

Sweet cherry cultivars grown in Northern Michigan in 1992 were analyzed for sensory and physicochemical characteristics. ‘Emperor Francis’, a yellow/red blushed, light color cultivar had the highest Brix/acid ratio at the 4th harvest, and it scored higher in sensory tests for sweetness flavor and overall acceptability than the dark cultivars, ‘Sam’ and ‘Hedelfingen’. Harvest dates showed significant effect on titrable acidity, Brix, Brix/acid ratio, sugars, weight and diameter of fruits. Brix/acid ratio showed significant correlation with sweetness. Correlation coefficients between overall consumer acceptability and measured parameters for three sweet cherry cultivars indicate that firmness has potential as an objective overall index for acceptability.     

LIPID AND AROMA COMPOSITION OF BLACK CUMIN (NIGELLA SATIVA L.) SEEDS FROM TUNISIA

The chemical composition of Tunisian Nigella sativa L. seeds was investigated. The results showed that linoleic acid (C18:2) was the major fatty acid with 65.1% of total fatty acids (TFAs) followed by oleic acid (C18:1) with 12.7% of TFAs. Neutral lipids (NLs) were mainly composed of triacylglycerols with 98.4% of total NLs. Polar lipids were mainly composed of phosphatidylcholine as the major phospholipid subclass, whereas digalactosyldiacylglycerol was the major galactolipid. Total sterols (TSs) represented 2.2% of the fixed oil and were composed of (-sitosterol as the major sterol representing 60.2% of the TSs. The results indicated that the sterols were mainly present in the esterified and in the free forms with 51.2 and 36.1%, respectively, of TS content. Finally, the aroma composition of the volatile oil from oleoresin exhibited the presence of many bioactive compounds such as p-cymene as the major component followed by ocimene, α -thujene, octen-3-ol with appreciable rates of 1,8-cineole and thymol.

PRACTICAL APPLICATIONS

The results obtained showed that Nigella sativa L. seeds were a good source of polyunsaturated fatty acids (PUFAs), phytosterols (PSs) and phospholipids (PhLs) for the human diet. These seeds could be used by the food industry for formulating functional foods enriched with PUFAs and PSs. For pharmaceutical applications, N. sativa L. conjugated sterols could be used as precursors for the hemisynthesis of many hydrosoluble steroids. Also, N. sativa L. seeds are a good source of PhLs and aroma compounds, and therefore, they could be utilized in biscuit manufacturing and in food flavoring. The presence of many bioactive compounds in N. sativa L. essential oil (p-cymene, limonene, α-pinene, linalool and thymol), known for their powerful antimicrobial function, could support the utilization of the essential oil bactericidal agents.