Pushkar Singh Bora

Functional properties of native and succinylated lentil (Lens culinaris) globulins

The functional properties of native and succinylated lentil globulins were evaluated. Succinylation caused a shift in the isoelectric pH of native globulins from 4.5 to 3.5 and improved the solubility above pH 4.0. However, below this pH the solubility of succinylated globulins was reduced. The water absorption and the viscosity of the sucinylated globulins were increased by almost 100%, while there was a decrease in the oil absorption capacity. The extent of succinylation used in this study did not show any significant relationships to these functional properties. Emulsion activity was also increased by succinylation; being 54.1% for the native globulins, 60% for the 57.9% succinylated globulins and 62.7% for the 87.2% succinylated globulins. Similarly, the emulsion stability was also improved. Foaming capacity of the succinylated globulins was decreased slightly, while foam stability, except at pH 2.5, was considerably reduced. Native and succinylated globulins showed maximum foam stabilities at pH 3.5 and 2.5, respectively.

Characterisation of some nutritional constituents of melon (Cucumis melo hybrid AF-522) seeds.

Abstract Seeds from a melon hybrid AF-522 largely cultivated in the northeast region of Brazil were analysed for their proximate composition. The seeds contained high percentages of lipids (30.8%) and proteins (14.9%). Hexane-extracted oil had acid, peroxide, iodine and saponification values of 2.06, 4.96, 111.8 and 210.6, respectively. Gas chromatographic analysis of the oil revealed the presence of 24 fatty acids varying from C 6 to C 24 with the exception of C 11 , C 19 , C 21 and C 23 . The concentrations of individual fatty acids varied from trace quantities to about 64%. Linoleic, oleic, palmitic and stearic acids were the principal fatty acids contributing to 64.1, 19.4, 9.5 and 4.9%, respectively, of the total fatty acids which had a relatively high percentage (84.4%) of unsaturated fatty acids. Seed proteins were rich in arginine, aspartic and glutamic acids while limiting amino acids were methionine and lysine.

Characterization of principal nutritional components of Brazilian oil palm (Eliaes guineensis) fruits

In spite of the fact that most of the members of Palmaceae contain high concentrations of oil, its potential as a source of oil and protein for human consumption has not been exploited. The pulp and kernels of the Eliaes guineensis palm fruits grown in the Northeast region of Brazil were analyzed only for their proximate composition. The lipid content of the dried pulp and kernels was 73.2% and 32.6%, respectively. Hexane extracted oils from the pulp and kernels yielded similar refractive indices, specific gravity but different peroxide, acid, iodine and saponification values. Gas chromatographic analysis revealed the presence of 24 and 18 fatty acids in pulp and kernel oils, respectively. The principal saturated acid of the pulp oil was palmitic acid (36.9% of the total), and lauric acid (53.3%) for kernel oil. Oleic acid was the predominant monounsaturated fatty acid in both the oils though its concentration in the pulp and kernel oils was 45.29% and 5.5%, respectively. In relation to the essential amino acids, pulp proteins presented a better profile than the kernel proteins. In comparison to the FAO reference protein, the pulp proteins were deficient in methionine, lysine and threonine (16.8%, 51.6% and 93.5% of FAO reference protein) but contained leucine, valine, isoleucine and phenylalanine in optimal concentrations. With exception to phenylalanine and valine (102.2% and 111.4% of reference protein, respectively), the kernel proteins were deficient in all other essential amino acids. The oils from this palm can be used as culinary oil and in margarine manufacture, while pulp could be a supplement for essential amino acids leucine, isoleucine, phenylalanine and valine with other protein sources that are deficient in these amino acids.

MACAIBA PALM: FATTY AND AMINO ACIDS COMPOSITION OF FRUITS MACAÍBA: COMPOSICIÓN DE AMINOÁCIDOS Y ÁCIDOS GRASOS DE FRUTOS MACAÍBA: COMPOSICIÓN DE AMINOÁCIDOS E ÁCIDOS GRAXOS DE FROITOS

Abstract The lipid content of dried pulp and kernels of Acrocomia intumescens palm fruits grown in the Northeast region of Brazil was determined to be about 34.6 and 49.2.6%, respectively. The hexane extracted oils from these parts showed refractive indices - 1.4427 and 1.4310, specific gravity - 0.9012 and 0.9213, peroxide - 2.96 and 1.37, acid - 1.5 and 2.1, iodine - 77.1 and 18.0, and saponification values - 158.0 and 230.4 respectively. Gas chromatography analysis showed a total of 24 and 18 fatty acids in pulp and kernel oils, respectively. The fatty acid composition of the pulp and kernel oils was 18.6 and 78.9% saturated, 65.5 and 20.0% monounsaturated 15.6 and 0.0% polyunsaturated, respectively. The principal saturated acids in pulp and kernel oil were palmitic and lauric acid with 13.3 and 45.5% of total fatty acids. Oleic acid was the predominant monounsaturated fatty acid in both oils with a concentration of 63.2 and 19.7%, respectively. The amino acid profile of pulp proteins was superior to kernel proteins, but contained only 49.5 of the methionine, 59.1 of he lysine and 96.2% of the valine found in the FAO reference protein. However, it contained leucine, isoleucine phenylalanine and threonine at 117, 136, 183 and 124% of the reference protein. The kernel proteins were deficient in essential amino acids with the exception of phenylalanine and isoleucine found at 156 and 101% of the reference protein, respectively.

Variation in physical and chemical composition during maturation of umbu (Spondias tuberosa) fruits

Abstract The fruits of the umbu ( Spondias tuberosa Arruda Camara), also known as ‘imbu’ in English, were analysed for some physical and chemical changes during various stages of maturity. The fruit was found to be round to ovoidal in shape, being, on average, 3.21 cm long and 2.86 cm in width. Half-ripe fruits contained the maximum (64.62%) pulp content. The pH of the fruits increased with the advance in maturity and ripe fruits were significantly less acidic than green mature and half-ripe fruits. Ripe and half-ripe fruits contained significantly higher reducing sugars (5.34 and 4.14%, respectively) than green mature (2.79%) fruits.

Changes in physical and chemical composition during maturation of yellow mombin (Spondias mombin) fruits

Abstract Yellow mombin (Spondias mombin L.) fruits were analyzed for some physical and chemical changes during various stages of maturity. The fruit was found to be ellipsoidal to ovoidal in shape, being, on average, 3·47 cm long and 2·65 cm in width. The weight of the pulp increased during ripening from green mature (40·67%) to the ripe stage (59·67%). The weight of the seeds and skin did not show any significant difference in green mature and half-ripe fruits. ° Brix acidity ratio increased with the advance in maturity. Half-ripe fruits had significantly higher (6·02%) reducing sugars than green mature (4·81%) and ripe (5·21%) fruits.

Note: Influence of pH on the extraction yield and functional properties of Macadamia (Macadamia integrofolia) protein isolates

Three protein isolates from de-fatted macadamia nut kernel flour were prepared by extraction at acidic (pH2.0), neutral (pH7.2 with 0.2M phosphate buffer containing 0.5MNaCl) and alkaline (pH12.0) conditions. Extraction at pH2.0 solubilised nearly 52.0% of the proteins present in defatted macadamia flour, while extraction with buffer (pH7.2) and alkaline pH (12.0) solubilised about 83.0% of proteins. The yield of isoelectrically precipitated protein from acidic extract (pH2.0, isolate A) was about 65.2% and from neutral (isolate B) and alkaline extracts (isolate C) was slightly over 83.0% which accounted for 33.7, 69.1 and 69.4% of the proteins present in defatted flour. The protein content of the isolates was 80.1, 92.1 and 92.0% in A, B and C isolates respectively. The functional properties of these isolates were significantly different. Isolate A presented better solubility at pH below isoelectric pH, isolate C at pH above isoelectric pH and isolate B intermediate solubility at the pH range studied. Isolate B showed best water and oil absorption capacities followed by isolate C and least by isolate A. For each isolate, the emulsifying properties were also significantly different at different pH values.

Postharvest respiratory activity and changes in some chemical constituents during maturation of yellow mombin (Spondias mombin) fruit

Mature fruit from the yellow mombin (Spondias mombin) was monitored for its respiration activity. Mature green fruit from the yellow mombin was stored in closed glass chambers and the concentration of oxygen and carbon dioxide at the end of a six hour respiration period was determined. At the same interval of time, the lid of the chamber was opened for air renewal. The increase in carbon dioxide and decrease in oxygen concentration demonstrated that the fruit was climacteric. The maximum liberation of CO2 54.2 mL Kg -1 h-1 and maximum absorption of O2 49.0 mL Kg -1 h-1 occurred 186 hours after the harvest which, obviously, represented the optimum fruit quality after the senescence process started. The respiratory quotient of fruit at a climacteric maximum was 1.11 representing the oxidation of carbohydrates. Total soluble solids increased from 9.1 °Brix (initial) to 13.7 °Brix (climacteric maximum) during maturation, while the total number of acids in the fruit decreased during maturation i.e. from 1.55% initially to 1.40% at pre-climacteric, 1.0% at climacteric maximum and 0.8% in the post-climacteric stage. A similar behaviour was observed in the case of ascorbic acid. There was a continuous decrease in chlorophyll and a continuous increase in the carotenoid content of fruit during maturation.

Extração, atividade da bromelina e análise de alguns parâmetros químicos em cultivares de abacaxi

Due to the risks and limitations which has come from exclusive cultivation of Perola and Smooth Cayenne - pineapple plant - and aiming genetic variability, the state of Paraiba provides diversified genetic material cultivating the hybrids Emepa - 01, Imperial and MD-2 pineapple varieties. Aiming the biochemical characterization of those new hybrids, some biochemical parameters were determined: pulp and rind of those cultivars including bromelain activity. Smooth Cayenne pineapple had introduced the smallest pH (3,44 for pulp and 3,91 for rind) and the biggest titled acidity (0,56g of citric acid for 100g of pulp and 0,52g of citric acid for 100g of rind), being the most acid cultivar. Among the pulps the Perola and the Smooth Cayenne varieties presented levels of reduced, non-reduced and total sugar significantly higher (p<0,05) than the hybrids, in spite of having more elevated values (bigger than 30,00) of the ratio of soluble solids to titled acidity, consequently resulted on a better acceptation by consumers. The crude extract of the Imperial cultivar had the biggest proteolytic activity and protein content in the pulp (56,41 U/ml and 7,50 mg of protein/mL) as well as in the rind (68,56 U/mL and 10,40 mg of protein/mL). For the specific activity, the rind of Perola pineapple (10,01 U/mg of protein) provided more significantly elevated value (p<0,05) than those ones observed in the other samples. However, the pulp from Imperial cultivar (7,49 U/ mg of protein) presented considerably superior activity if compared to the rest.

Functional characterization of acetylated Brazil nut (Bertholletia excelsa HBK) kernel globulin

Farinha desengordurada de amendoa de castanha-do-Para, fonte rica de proteina de alta qualidade, vem sendo, atualmente, aproveitada apenas na formulacao de racao animal. Uma das possiveis maneiras de melhorar seu aproveitamento para o consumo humano e atraves do melhoramento de suas propriedades funcionais. No presente trabalho, mudancas em algumas propriedades funcionais da globulina de castanha-do-Para, apos acetilacao, aos niveis de 58,6, 66,2 e 75,3% foram estudadas. A solubilidade da globulina acetilada aumentou acima de pH 6,0, porem diminuiu na faixa de pH 3,0 a 4,0. As capacidades de absorcao de agua e de oleo como tambem a viscosidade, melhoraram com o aumento de grau de acetilacao. O grau de modificacao tambem influenciou a capacidade de emulsificacao: reduziu em pH 3,0, e aumentou nos pHs 7,0 e 9,0. A maxima atividade de emulsao (aproximadamente 62,2%) foi observada em pH 3,0 seguida de pH 9,0 e a minima foi observada (11,8%) em pH 5,0. A estabilidade de emulsao tambem apresentou o comportamento similar a atividade de emulsao.