Nutritional, sensory, physico-chemical, phytochemical, microbiological and shelf-life studies of natural fruit juice formulated from orange (Citrus sinensis), lemon (Citrus limon), Honey and Ginger (Zingiber officinale).

Orange (Citrus sinensis), lemon (Citrus limon), ginger (Zingiber officinale) and honey contain nutrients and phytochemicals that are beneficial to health. Most of the available fruit drinks are artificial and may contain a lot of chemicals which could be unhealthy and detrimental to the health of the consumers. This work was aimed at formulating a healthy fruit drink from the combination (blend) of orange, lemon, ginger and honey for the development of a new product. Thirty (30) different juice blends (formulae) were made and subjected to sensory evaluation, from which five best formulated juices were selected using a 9 point hedonic scale. These were then subjected to physicochemical, nutritional, phytochemical, microbiological analyses and shelf-life studies. The results of the study showed pH (3.40-4.90), Vitamin C (0.04-0.06 mg/mL), titrable acidity (0.04-0.21 citric acid mg/100mL), total soluble solids (2.90-20.69%), reducing (0.41-1.44 mg/mL) and non-reducing sugar (0.21-2.06 mg/mL). The moisture, protein, fat, ash, fibre and available carbohydrate contents ranged from 79.31-97.10 %, 0.01-0.56g/100mL, 0.05-0.11g/100mL, 0.51-1.13g/100mL, 0.01-0.09g/100mL and 16.39-22.99g/100mL respectively. The macro (K, Ca, P, Na) and micro (Zn, Fe) minerals varied differently with Potassium (K) being the most abundant. Amongst the five best formulated juices, F22 (5% lemon juice) was the most organoleptically accepted. On the other hand, F21 (10% lemon juice + sugar) which had the least overall acceptability amongst the five, was shown to be the most nutritive.

Effect of Syzigium aromaticum and Allium sativum spice extract powders on the lipid quality of groundnuts (Arachis hypogaea) pudding during steam cooking.

Groundnut seeds (Arachis hypogaea) contain higher concentrations of unsaturated lipids which are prone to oxidation in formulated foods. This study determined the antioxidant activities of water extract powders from two spices (Syzigium aromaticum and Allium sativum) and their ability to preserve the quality of lipids in groundnuts pudding during steam cooking with 0, 0.5, 1, 2 and 4% of spice extract powders. Total phenolic (TPC) and flavonoid (FC) contents of extracts from S. aromaticum were 140.23 mg GAE/100g extract and FC of 110.34 mg CAE/g extract compared to values of Allium sativum extracts (54.28 mg GAE/100g extract and 34.80 mg CAE/g extract). The showed DPPH free radical scavenging activities of the extract from S. aromaticum depending on the concentration ranged from 82.15% to 97.66% and this was higher than the activities of A. sativum but comparable to the values of buthylhydroxytoluene used as control. The chemical analysis of oil extracted revealed that the addition of the spice extract powders limited the appearance of oxidation products characterized by a reduction of up to 9-fold of peroxide value, 5-fold for anisidine and 2-fold for thiobarbituric acid reactive species. In many cases, the addition of S. aromaticum spice extract powder to the pudding better prevented lipid oxidation likely because of its superior ability to scavenge peroxyl radicals (ROO., HO., DPPH . ). In a nutshell, the addition S. aromaticum and A. sativum spice extract powders on grilled groundnuts paste for groundnuts pudding preparation in household can help preserve its lipid quality.

Optimization of the extraction of natural antioxidants from Coffea robusta leaves and evaluation of their ability to preserve palm olein from oxidation during accelerated storage.

Response surface methodology (RSM) was used to optimize the extraction of phenolic antioxidants of Coffea robusta leaves and to evaluate the effect of optimized extract and storage time on the stability of palm olein. The optimization of the extraction process was conducted, and the total polyphenol value of 127.06 mg GAE/g and scavenging activity of 90.65% were obtained under optimal extraction conditions. The phenolic antioxidants of the optimized extract and their thermal stability were determined using HPLC-DAD (high-performance liquid chromatography-diode array detector) and Rancimat test, respectively. The effect of concentration of the optimized extract and storage time on the stability of palm olein was also evaluated. Results showed that the optimized extract contains gallic acid, vanillic acid, cafeic acid and was efficient in retarding palm olein oxidation during 32 months at room temperature. Coffea robusta can be recommended as good source of antioxidants for stabilization of palm olein.

Effect of traditional and oven roasting on the physicochemical properties of fermented cocoa beans.

The objective of this study was to determine the effect of oven and traditional roasting on the polyphenol content, antioxidant activity, lipid quality, proximate composition and mineral content of fermented cocoa beans. Results showed that traditional roasting significantly decrease (p < 0.05) the polyphenol content and antioxidant activity of cocoa beans. The analysis of oil showed that oven and traditional roasting significantly increase (p < 0.05) the peroxide and thiobarbituric acid values of cocoa butter and that traditional roasting samples were the most deteriorated. Oven and traditional roasting for 10 min reduce the iodine value of the oil, but increase its acidity. The proximate and mineral composition of cocoa beans was also seriously affected during cooking. Drying and oven roasting for 5 and 10 min; and drying and traditional roasting for 5 min appear to be the best processing methods of cocoa beans for production of cocoa based foods like chocolate.