ABSTRACT

Under nutrition and micro nutrient deficiencies continue to be a problem worldwide, particularly in developing economies, including Nigeria.  Economic losses caused by post- harvest losses are heavier than is generally realized because fresh fruits deteriorate in unit value from the field from harvest to the consumer. These necessitated this study to evaluate the chemical composition and sensory properties of juice, drink, jam and marmalade from African wild black plum (Vitex doniana) and Star fruit (Averrhoa carambola). V. doniana and A. carambola fruits picked from their trees in Federal College of Agriculture, Ishiagu, Ebonyi State and Umuokpara Umuahia South LGA of Abia State respectively. The V. Doniana fruits were sorted, washed, peeled and the pulp was scooped out and processed while the seeds of the carambola were removed before processing into juice, drink, jam and marmalade. Products were blended in 100%, 75%/25%, 50%/50% & 25/75% of Vitex doniana and Averrhoa carambola fruits. Proximate compositions, minerals, vitamins, antinutrient factors, physicochemical, physical, microbial and sensory properties of the products were evaluated using standard procedures. Controls used were purchased from commercial stores (Orange/Mango juice (UC), Blackberry/grape/blackcurrant/raspberry drink (DC), Blueberry/apple jam (JC) and Orange marmalade (MC). Sensory evaluation was done with 20 panelists on a 7-hedonic scale. Data obtained were statistically analyzed using SPSS 20.0. Results showed the controls had higher moisture, ash and crude protein in juice, drink, jam and marmalade while the Vitex/Carambola (VC) samples had higher values of crude fibre, fat, carbohydrate and energy. The controls had higher mineral values than the Vitex/Carambola samples in sodium, potassium, phosphorus, calcium, copper, iron, magnesium and zinc in all the products of respectively. The controls also had higher values of B1, B2, B3 in all the products respectively. The controls had higher Beta-carotene in juice and jam; higher vitamin C in drink, jam and marmalade while VC samples had higher values of vitamin C in juice. The products also have high beta-carotene in drink and marmalade.  The VC samples had low antinutrient values in saponin (0.53mg, 0.58mg, 0.37mg and 0.30mg), phytate (0.55mg, 0.45mg,0.20mg and 0.17mg), oxalate (0.77mg, 0.92mg, 0.31mg and 0.23mg), phenol (23.26mg, 23.44mg, 13.67mg and 12.29mg) and tannin (0.24mg, 0.24mg, 0.14mg and 0.14mg) respectively, although the values were higher than the controls. In physicochemical properties, VC samples had higher values of pH while controls had higher values of titratable acidity and total soluble solids. The VC samples had higher values in the physical properties except in juice. These bacteria (Streptococcus, Staphylococcus aureus, Proteus spp., Klebsiella sp., E. coli, Pseudomonas) and fungi (Penicillin, yeast, Aspergillus niger, Rhizopus spp and Trichoderma) were found in the VC samples while (Streptococcus, Staphylococcus aureus, Klebsiella spp, Proteus spp.) and (Penicillin, Aspergillus niger and yeast) were found in the control at tolerable limit. A general reduction in the chemical compositions was observed during storage for 30 and 60 days. The sensory evaluation of drink, jam and marmalade showed no significant differences (p>0.05) between the control and VC samples except in juice. The fruits products were accepted by the panelists.