Characterization and optimization of carotenoid extracted from the peels of tomato Lycopersicon esculentum grown in Nigeria

The application of synthetic colourants to foods, snacks, and beverages has increased within the past 50 years, and up to a 500% increase has been  reported in Nigeria. Consumers of coloured foods and beverages have been showing worries about the possible health hazards of such products  over time. Hence, researchers have shifted attention to alternative and natural colourants that are harmless. Extraction of carotenoid from tomato  peel by-product will not only solve the problem associated with consuming synthetic colourant but solve the pollution problem connected with  tomato processing. This research was conducted to study the kinetics and determine the thermodynamics of carotenoid extraction from tomato  peel (Lycopersicon esculentum) using ethanol. Tomato peel by-product was collected, cleaned, oven-dried, and ground. It was characterized to  determine the proximate and phytochemicals composition. The carotenoid extraction process parameters were optimized using response surface  methodology, and the carotenoid extracted was analysed using a gas chromatographmass spectrophotometer. The kinetics and thermodynamics of  extraction were studied using a first-order mass transfer model and thermodynamics to determine energy changes involved in the extraction.  The result of the proximate analysis showed the following values; crude protein (0.69%), Fibre (20.63%), Ash (17.40%), Fat (8.53%), Moisture (8.13%),  and Carbohydrate (44.62%). The phytochemical analysis showed that the tomato peel contains terpenoid, alkaloid, saponin, and flavonoid. The  optimal conditions for carotenoid extraction were 0.306 mL/g solvent/solid ratio, 20 minutes extraction time, and temperature of 36 °C with the  optimal yield of 82.35%. The result indicates that tomatoes contain 82.35 g of carotenoid. It is observed that the carotenoid contains lutein 1.89%,  lycopene 88.11%, - carotene 2.25%, cis--carotene 2.41%, - carotene 1.23%, cis-lycopene 0.89%, phytofluene 0.62%,-carotene 1.2% and phytoene  1.52%. Therefore, among the components, lycopene is the most dominant with the composition of 88.11% yield, and the extraction was  endothermic, spontaneous, and feasible. Ethanol is a good solvent for the extraction of carotenoid from tomatoes peel. &nbsp

Quality of Cookies Produced from Blends of False Yam (Icacina tricachantha) and Wheat Flours

This study evaluated the cookies produced from blends of processed false yam  (Icacina tricachantha) and wheat flours. False yam tubers were peeled, washed, cut into pieces and steeped in clean water for 24 h. The steeped false yam was oven dried and pulverized into flour. The flour was blended with wheat flour at ratios of 100:0, 90:10, 80:20, 70:30, 60:40 and 50:50% of wheat and false yam flour, respectively. Each of the flour blend was used in cookies production. Proximate, physical and sensory properties of the cookies were evaluated and data generated were statistically analysed. The result of proximate composition of cookies ranged from 7.8 to 10.22%, 6.15 to 10.66%, 8.63 to 9.21%, 2.41 to 2.74%, 1.57 to 1.67%, 65.95 to 72.86%, 377.94 to 400.59 kcal and 90.79 to 91.37% for crude protein, fat, moisture, ash, crude fibre, carbohydrate, energy value and dry matter, respectively. Moisture and carbohydrate contents increased (p<0.5) with increase in false yam substitution of wheat. The result of physical properties showed that weight (54.20-39.99g), diameter (6.92-7.10 cm), spread ratio (9.61-9.79) and breaking strength (10.28-12.11 g) of the cookies increased (p< 0.05) with increase in false yam substitution up to 30%. Sensory evaluation results revealed that the reference sample (100% wheat) scores were not significantly (p>0.05) different from 10% wheat substituted cookie scores except for taste. In conclusion, the result indicated that good quality cookies could be produced from blends of wheat and false yam flours.Keywords: False yam, processing, blends, cookies and quality

Physicochemical and sensory characteristics of Roselle fortified yoghurts stored in refrigerator

Background: Cow’s milk yoghurt is nutritionally rich in protein and micronutrients but has poor keeping quality and is devoid of most bioactive constituents present in plants. Phenolic bioactive constituents could enhance shelf life of yoghurt and promote health of consumers. Objective: The study evaluated the effects of roselle calyx on the physicochemical and sensory properties of yoghurts stored in a refrigerator at 40C. Methods: Ten (10), 20 and 40 grams of ground roselle calyx, were separately boiled in 100ml distilled water for 20mins, cooled and juice extracted overnight (14hours) before filtering through muslin cloth. Each filtrate was boiled (10 mins), cooled and made up to 1litre with distilled water; mixed with 125g full cream powdered cow’s milk and used to produce yoghurts coded B, C and D. A control full cream powdered milk with no roselle was also produced and coded A. The yoghurts were pasteurized (85OC for 15 mins), fermented (44OC for 7hours), cooled to set and analysed for quality characteristics during10 days refrigerated storage. Results: Moisture content of yoghurts increased from 96.11% in yoghurt D to 98.83% in A and was significantly (p < 0.05) higher in A than in the roselle-treated samples. Roselle addition above 1% significantly (p < 0.05) improved the phenol content and viscosity (cp) but decreased syneresis of the yoghurt samples proportionally. Flavour and texture of the yoghurts were also improved. However, the control was most acceptable. Conclusion: Roselle addition improved quality of plain cow’s milk yoghurt and is recommended for its bioactive polyphenols.Key words: Quality characteristics, roselle-fortified, yoghurt, storag

Effect of fermentation media and time on physicochemical and sensory properties of soybean powders

Fermentation improves quality of food, and is exploited in processing soymilk powder. Unfortunately, there is no unified fermentation procedure for producing powdered soymilk in Nigeria. A fermentation condition to produce high nutritional and most acceptable powdered soymilk is ideal for Nigerians. This study evaluated the effect fermentation media and time on physicochemical and sensory properties of powdered soymilk. Seven batches (600 g each) of soybean seeds were fermented, the first three in neutral water, sample A for 4 h, B for 16 h in the same water, and C for 16 h but changing the water every 4 h. The next two were fermented in alkaline solution for 16 h, D in the same water, and E with changing the water every 4 h. The last two were fermented for 16 h in acidic solution, Fin the same solution and G with changing the water every 4 h. The beans were processed into cooked soy flour and analyzed for physicochemical and sensory properties. Fermentation enhanced better quality than soaking; fermentation time and medium pH significantly (p < 0.05) induced variations in quality of the powder. Soaking produced soy powder with highest carbohydrate (44.47 %) and fibre (1.355%) but significantly (p < 0.05) low in protein, minerals and crude fat. Continuous 16-h fermentation in the same medium produced soy powders with lowestphytochemical contents. Soaked (4 h) soybean in neutral water (A) produced powder with 39.50% protein, 44.47% carbohydrates, 1.35% fibre, 5.58% fat and 2.75% ash while continuous fermentation for 16 h in the same water produced powder (B) with 42.47% protein, 41.71% carbohydrate, 1.22% fibre, 5.81% fat and 2.42% ash. Continuous 16-h fermentation was better than changing the medium; and neutral medium was better than acidic and alkaline medium. All the soy powder high sensory scores (≥ 5) and were acceptable to the panelists. Thus, 16-h continuous fermentation in neutral medium was more cost effective and produced soybean powder of better quality than fermenting in alkaline and acidic media. Key words: fermentation time, quality, soaking media, soybean powder

Production and quality evaluation of soy milk yoghurt

Background: Yoghurt is a fermented dairy product basically produced from cow's milk. In Nigeria, cow’s milk is imported and relatively expensive. Soy milk is inexpensive and available and could be alternative to cow's milk in yoghurt production. Objective: This study evaluated nutrient composition and sensory characteristics of soy milk yoghurt. Methods: Soy milk (4.6litres) of 12.5% total solid was produced from 500g of soybean seed using standard method and divided into 3 portions (C1, C2 and C3) of 1000ml each. Liquid cow’s milk was made by mixing 125g of full cream powdered milk with1litreof distilled water; and designated B. The C1, C2, C3 and B, were separately pasteurized (85o C, 15 mins), homogenized, cooled to 40 – 44o C and inoculated with 0.44% of 50:50% mixture of Lactobacillus bulgaricus and Streptococcus thermophillus. Sucrose (1.95g), carboxyl methyl cellulose (CMC) (0.96g) and strawberry (2.5ml) and commercial cow's milk flavour (0.10g) were added to samples C1, C2 and C3 while lactose and calcium citrate were added only to C2 and C3 at different concentrations. These were fermented (7h), cooled (44o C) gradually to set. The yoghurts were analyzed for nutrient composition, microbial and sensory quality. Results: Soy milk yoghurt which had no CMC was relatively higher in carbohydrate (50.01%) than others which had 2.85% to 4.84% carbohydrate. The sensory attributes of the formulated samples were affected by ingredients, but they compared favourably with the cow's milk yoghurt. Conclusion: The produced soy milk yoghurts had nutrient and sensory quality characteristics similar to cow's milk yoghurt and could be substitute cow's milk yoghurt.Keywords: Production quality evaluation, soy milk yoghurt