Saka O. Gbadamosi

Studies on the Osmotic Dehydration and Rehydration Characteristics of Pineapple Slices

The study investigated the influence of two osmotic conditions (50°Brix sugar and 47:3% w/w sugar/salt solutions) on osmotic dehydration (water loss, solid gain, electrical conductivity and pH of the medium) and rehydration characteristics (Dry-matter loss, rehydration capacity, electrical conductivity and pH of the medium) of dried pineapple slices. Pineapple slices were osmotically dehydrated (4 hr), and oven dried (60°C for 27 hr). Slices were rehydrated at 90°C for 15 min and at room temperature (RT) for 6 hr. Osmotic dehydration enhanced solid gain, water loss, dry-matter loss and rehydration capacity. Mass transfer (water loss and solid gain) was higher in sugar/ salt solution than in the sugar solution. Sugar/salt mix reduced the amount of electrolytes released into the medium. Regression models gave a good fit of high R2 value when water loss, solid gain, and electrical conductivity variables were related, but dry-matter loss, rehydration capacity, pH and electrical conductivity gave low R2 values.

Studies on Chemical Constituents and Nutrients Bioavailability in Moringa oleifera Leaf and Seed

Aims: The aim of this study was to evaluate and compare the nutritional composition, antinutritional factors and antioxidant potentials of the bioactive compounds of Moringa oleifera (M. oleifera) seeds and leaves. Place and Duration: The study was carried out in the department of Food Science and Technology, Obafemi Awolowo University, Ife, Nigeria, between March-September, 2014 Methodology: M. oleifera leaf powder and seed flour were obtained by drying fresh leaves and seeds in a hot air dryer and milled. The seeds and leaves were characterized and analysed using standard methods. Results: The results showed that the crude protein, total ash, and crude fat contents of M. oleifera leaf were 20.29±0.41, 7.27±0.25 and 1.79±0.17% while those of the seed were 33.82±0.21, 5.17±0.41 and 38.69 ±0.38%, respectively. Calcium content of the seed Original Research Article Oladeji et al.; JSRR, 14(1): 1-12, 2017; Article no.JSRR.32458 2 (46.93±0.18 mg/100 g) was relatively low when compared with that of the leaf (521.96±0.32 mg/100 g). Zinc and iron concentration (14.72±0.12 and 8.12±0.11 mg/100g) in the seed were higher than in the leaf (12.28±0.02 and 7.86±0.62 mg/100g for Zn and Fe respectively). In the leaf and seed, alkaloids (0.428±0.13 and 0.597±0.04%), saponin (2.860±0.11 and 0.295±0.02%), and tanin (mg/g) were within the consumable limit. Phytate content of the leaf (0.4267±0.02 mg/g) and seed (0.4905 ±0.06 mg/g) were low enough to permit bioavailability of phosphate and not impair calcium and zinc bioavailability but may lower iron absorption in the body. Proportion of phosphate as phytate (11.95 and 13.73 mg/100g for leaf and seed respectively) was low indicating high bioavailability of phosphate. 2, 2-Diphenyl-1-picryl hydrazyl (DPPH) radical scavenging activities of the leaf and seed were 83.61±0.31 and 69.84±1.08% respectively implying the seed and leaf possess noteworthy antioxidants activity. Conclusion: The study implies that M. oleifera leaf and seed from South Western, Nigeria are suitable for consumption with great health benefits.

Chemical Composition and Quality Characteristics of Wheat Bread Supplemented with Leafy Vegetable Powders

The study investigated the effect of supplementation of the leaf powders of Telfairia occidentalis, Amaranthus viridis, and Solanum macrocarpon on the chemical composition and the quality characteristics of wheat bread. The bread samples were supplemented with each of the vegetable leaf powders at 1%, 2%, and 3% during preparation. The bread samples were assayed for proximate composition, mineral composition, physical, sensory, and antioxidant properties using standard methods. The addition of vegetable powders significantly increased the protein (9.50 to 13.93%), fibre (1.81 to 4.00%), ash (1.05 to 2.38%), and fat (1.27 to 2.00%). Supplementation with vegetable powder however significantly decreased ( ) the carbohydrate and moisture contents. Significant ( ) increases were recorded for all evaluated minerals as the level of vegetable powder increased. Supplementation with vegetable powder caused significant decrease in total phenolic content, percentage DPPH inhibition, metal chelating ability, ferric reducing antioxidant power, and total antioxidant capacity. Sensory results showed that there was significant decrease in sensory qualities with increasing supplementation. This therefore suggests that bread supplemented with vegetable powder could have more market penetration if awareness is highly created.

Characterization and antioxidant evaluation of phenolic compounds extracted from the protein concentrate and protein isolate produced from pawpaw (Carica papaya Linn.) seeds

ABSTRACT In this study, the qualitative and quantitative analysis of the absolute (100%) and aqueous (80%) methanolic extract of Carica papaya Linn processed seed flour samples in terms of their antioxidant properties and their phenolic compounds was investigated. The antioxidant properties were determined by 2,2-diphenyl-1-picrylhydrazyl (DPPH), ferric reducing antioxidant power, and metal chelating assay methods. The protein isolate exhibited higher radical scavenging activity power as compared to other samples. Ferulic acid, caffeic acid, p-coumaric acid, kaempferol-3-glucoside, p-hydroxybenzoic acid, and quercetin-3-galactoside were phenolic compounds isolated with ferulic acid as high as 0.62 mg/DWg. Carica papaya seed isolates and concentrate demonstrated potent antioxidant activity and could be of nutraceutical importance in the pharmaceutical and food industry.

Effects of cooking and fermentation on the chemical composition, functional, and antinutritional properties of kariya (Hildergardia barteri) seeds

Abstract The effects of natural fermentation and cooking on kariya seeds functional properties, chemical composition, and antinutritional properties were evaluated. Result showed a reduction in antinutritional properties and improvement in protein content which were observed to increase with cooking (at 100°C) and fermentation period (24–96 hr). Functional analyses showed an increase in foaming and emulsion properties, while water absorption capacity and swelling power were observed to likewise increase with an increasing temperature between 60°C and 90°C. There was also an improvement in foaming properties with increase in salt (NaCl) concentration, while emulsifying property decreases with an increase in salt (NaCl) concentration. Based on the result of the findings of this study, it can be stated that the cooking and fermentation processes employed in this study can enhance the domestic and industrial utilization of these seeds.

Optimization of Production of Bread Enriched With Leafy Vegetable Powder

Box-Behnken design was used to study the effect of level of inclusion of dried leafy vegetable powder, mixing time and proofing time, on the weight, volume and specific volume of bread made from composite flour. Data obtained were evaluated using regression analysis. The study revealed all the parameters studied were significant in producing high quality vegetable powder enriched bread. The coefficient determination (R 2 ) was good for the second-order quadratic model. The study found out those combinations of the parameters; level of vegetable inclusion; 3.65%, proofing time: 90.6 minutes and mixing time: 4.04 minutes were the optimal conditions for the productions of high quality bread enriched with vegetable powder. The study further confirmed through additional analysis that the model is adequate to optimize the process.

Characterization of protein isolate from Sesamum indicum seed: In vitro protein digestibility, amino acid profile, and some functional properties

Abstract This work evaluated the impacts of pH and sodium chloride (NaCl) concentration on some functional properties, in vitro protein digestibility, and amino acid profile of sesame (Sesamum indicum) protein isolate (SPI) produced using simultaneous recovery of protein and oil technique. The emulsion activity index (EAI), foam capacity (FC), and protein solubility varied with pH and ionic ability. Foam capacity rose with an increase in ionic strength. Protein solubility ranged from 8.39% at pH 4 to 55.08% at pH 10. In vitro protein digestibility of the SPI with pepsin–pancreatin enzyme systems was 89.57%. Amino acid profile showed that essential amino acids constituted 39.48%. The amino acids had good scores well above 50%. The results showed that SPI extracted by aqueous technique could be used as food ingredient, particularly as thickener, binder, and ingredient in baked food products.

Extraction Optimization and Antioxidant Properties of African Eggplant (Solanum macrocarpon) Leaf Polyphenols

Optimization of the yield, total phenolic content (TPC), and total antioxidant activities (TAA) of polyphenol concentrates extracted from Solanum macrocarpon leaves was studied using response surface methodology. The process variables investigated included extraction temperature (30, 50, and 70°C), extraction time (2, 4, and 6 h), and dried leaf powder : water ratio (1 : 10, 1 : 20, and 1 : 30 w/v). Box–Behnken design resulted in 15 experimental runs. The results showed the following optimum extraction conditions: temperature, 49.05°C; extraction time, 243 min; leaf powder : water ratio, 1 : 22 w/v. The optimized extraction conditions gave polyphenol concentrate yield, TPC, and TAA values of 24.94%, 421.09 mg GAE/g, and 23.81 mg AAE/g, respectively. Results of the in vitro antioxidant activities of the polyphenol concentrate showed 2, 2-diphenyl-2-picrylhydrazyl hydrate, metal chelating ability, and ferric reducing ability values of 76.78%, 80.22%, and 56.46 mg AAE/g, respectively. The study concludes that the experimental values compared closely with the predicted values, which indicates suitability of the model employed for polyphenol extraction optimization from dried S. macrocarpon leaves.

Physicochemical and sensory properties of pineapple flavoured roselle powders

Abstract This study was carried out to determine the physicochemical and sensory properties of blends of roselle and pineapple powders. The blends were produced by adding powder from natural pineapple to the powder of roselle calyces in the proportion of 15, 20 and 25%. The proximate composition, vitamin C, pH, total soluble solids, bulk density, reconstitution index, particle size, titratable acidity and reducing sugars were determined using standard methods. The proximate compositions of the samples were in the range of 4.94–6.57% (protein), 63.41–67.22% (carbohydrate), 2.31–2.48% (fat), 9.23–10.34% (fibre), 8.04–9.93% (ash) and 7.44–8.09% (moisture). The vitamin C contents ranged between 67.23 and 76.88 mg/100 g. The pH, total soluble solids and reducing sugar increased significantly (p < 0.05) while the titratable acidity, bulk density, reconstitution index and mass mean diameter decreased significantly (p < 0.05) with increase in addition of pineapple powder to roselle powder. Based on sensory evaluators, the sample with 25% pineapple powder was the most preferred.

Effect of different treatments on in vitro protein digestibility, antinutrients, antioxidant properties and mineral composition of Amaranthus viridis seed

Abstract In recent times, only the leaves of Amaranthus viridis are been utilized, the seeds are usually discarded. Processing this seed will enhance its utilization as food or functional food. A. viridis seed with protein, fat, ash and carbohydrate content of 11.06, 7.30, 2.94, and 65.01%, respectively was subjected to autoclaving, fermentation, blanching, defatting, and germination. Changes in in vitro protein digestibility, antinutrients, minerals and antioxidant properties were investigated. All the processing methods increase the in vitro protein digestibility of the amaranths seed. There was significant reduction in tannin (13–56.5%), oxalate (10–46%), saponin (15–41%). Fermentation and germination significantly (p < 0.05) increase antioxidant activity (DPPH) and metal chelating activity. In contrast, thermal processing (autoclaving and blanching) significantly reduce the total phenolic compound and FRAP of the amaranth seed. In addition, the minerals composition of the seed was greatly affected by the processing methods. The study showed that germination provided a new approach to further develop A. viridis seed as a functional food for human consumption.