Effect of processing conditions on some quality attributes of fried cassava-defatted peanut crackers

A 23 full factorial design was used to investigate the effect of steaming time, dough slice thickness and frying time on some quality attributes of fried cassava-defatted peanut crackers. The sample mixture (cassava starch-75% and defatted peanut flour-25%) was worked up to a moisture content of 40.85%, formed into a sausage-like shape, steamed (40 and 80 min) and then refrigerated at 5 °C for 18 h. Refrigerated dough were sliced into different thicknesses (1 and 2 mm), dried at 60 °C for 4 h and then fried at 170 °C for between 10-20 s. Fried samples were analyzed for moisture and oil contents, expansion, texture, and colour. The effect of the variables was analyzed using ANOVA of Design expert version 12 after which regression models and response surface plots were generated. Optimized samples were obtained and sensory analyses of the sample were conducted. The regression equations were evaluated and verified to be accurate with high determination of coefficient of between 0.87 and 0.99. Linear model terms of steaming time, slice thickness and frying time significantly (p<0.05) affect oil content and texture while interaction of steaming time and slice thickness significantly (p<0.05) affect oil content. The optimized process conditions to obtain high nutritious and healthier fried cassava – defatted peanut crackers were 80 min, 1.00 mm and 10.02 s for steaming time, dough slice thickness and frying time, respectively.

Evaluation of lactic acid bacteria viability and anti-diarrhoeagenic Escherichia coli activities of non-alcoholic fermented beverage ‘Kunu’

Kunu is a non-alcoholic fermented cereal beverage consumed primarily as a refreshing drink. This study investigated the effects of storage conditions on viability of Lactic Acid Bacteria (LAB) in kunu and the antibacterial effects of Kunu against diarrhoea caused by Escherichia coli strains. Kunu was prepared according to local traditional method. Viability counts of LAB in kunu stored at two different conditions, cold (4 ℃ average) and room temperature (26 ℃ average), were evaluated. Isolated LAB from kunu were identified by partial sequencing of 16S rRNA gene. Five pathotypes of diarrhoea caused by E. coli strains were co-cultured with kunu to evaluate its antimicrobial activities. Viable LAB count in kunu ranged from 5.0 x 109 to 1.0 x 1011 cfu/mL. Pediococcus pentosaceus, Lactobacillus plantarum and Leuconostoc pseudomesenteroides were identified from kunu. There is a drastic decrease (2-5 log reduction) in E. coli strains co-cultured with kunu. The observed high viable counts of beneficial LAB in kunu with its antimicrobial activities against diarrhoeaogenic E. coli strains indicates that kunu is not just a refreshing drink, but it also has antimicrobial potential against diarrhoea caused by E. coli.

Physico-chemical and Sensory Properties of Cookies Produced by Partial Substitution of Margarine with Avocado Pear (Persia americana)

The partial substitution of margarine with mature avocado pear pulp in the production of cookies was investigated. Five cookie samples were produced with avocado pear pulp and margarine blends in the ratios 80:20%, 70:30%, 60:40%, 50:50%, and 100% margarine serve as the control, labeled as B, C, D and E and A, respectively while the other ingredients used remain constant. The physico-chemical (proximate compositions, free fatty acids (FFA), iodine value, and peroxide value) and sensory qualities of the cookies were evaluated using standard methods. The results show ranged in moisture (11.13 to 14.60%), crude protein (6.93 to 7.83%), crude fat (16.00 to 18.03%), ash (1.40 to 2.09%), crude fiber (0.29 to 0.62%), carbohydrate (59.70 to 62.79%), FFA (0.35 to 1.01 mg KOH/g), iodine value (75.63 to 81.17 g I2/100 g) and peroxide value (2.96 to 5.27 meq/kg). The partial substitution of margarine with avocado pear pulp produced nutritious cookies with desirable organoleptic qualities. Also, the results demonstrated that cookies had acceptability up to a 30% level of substitution with avocado pear pulp. The findings indicated the feasibility of avocado pear pulp in fat-reduced cookies preparation, this will reduce the pressure in using only margarine in cookies making and diversify the use of avocado pear.

Effects of freezing periods and polythene packaging with or without turmeric powder paste on proximate composition of Labeo bata fish

The study was designed to investigate the effects of freezing periods and the combination of packaging with or without turmeric on the proximate composition of whole and sliced Labeo bata. The samples were subjected to 28 days of frozen (-20 °C) storage periods and analyzed for proximate composition such as moisture, protein, lipid and ash at intervals of 0, 14 and 28 days. Data obtained was subjected to analysis of variance (ANOVA) at 95% significant level. Different preservation periods and methods significantly affected the nutritional composition of fresh fish. Moisture, protein, lipid and ash content decreased with increasing storage periods when compared to the fresh fish as control. The highest percentage of protein was found in turmeric-treated whole fish preserved in polythene, C4, after the 14th (15.70±0.14) and 28th (15.27±0.21) day. On the other hand, the lowest percentage (14.01±0.10 and 13.22±0.18 for the 14th and 28th day, respectively) was found in sliced fish preserved without polythene, C5. In conclusion, the turmeric-treated whole fish preserved in polythene retained fish nutrients and ensured its good quality and composition longer than other treatments, thereby extending the shelf life during frozen storage.

Effect of processing methods on the antioxidant potentials of netlespurge (Jatropha tanjorensis) and black nightshade (Solanum nigrium) vegetables in peanut burger

Two lesser known indigenous vegetables: netlespurge (Jatropha tanjorensis) and black nightshade (Solanum nigrium) were each processed into flour samples and were incorporated into wheat flour in coating peanut. These veggie peanut burgers were analysed for their antioxidant properties such as DPPH, FRAP and Metal Chelating ability assay and their linoleic acid inhibition. Veggie peanut burger with netlespurge vegetable had values between 44.62 to 68.32%, 0.0106 to 0.0253 mg AAE/g sample and 49.03 to 63.30% for DPPH, FRAP and Metal chelating assay, respectively, while veggie peanut burger with black nightshade had values between 54.97 to 72.70%, 0.0105 to 0.0173 mg AAE/g sample and 47.13 to 64.01% for DPPH, FRAP and Metal chelating assay respectively. The result of the inhibition of linoleic acid of the peanut burger incorporated with vegetables revealed the abilities of the vegetables to inhibit propagation of peroxides up till the fourth day. Netlespurge vegetable had absorbance values of 2.3220 µm initially rising to 2.6845 µm on the fourth day and a fall absorbance value of 1.1845 µm on the sixth day while Black Nightshade vegetable had absorbance values of 2.3670 µm initially rising to 2.7490 µm on the fourth day and a fall absorbance value of 1.2355 µm on the sixth day. This study concluded that processing methods does not eliminate the antioxidative properties of vegetables and the inclusion of vegetables into peanut burgers increased their antioxidative properties.

Optimization of cereal Blend (wheat and yellow maize flours (Zea maize)) enriched with African walnut (Tetracarpidium conophorum) protein isolate for cookie making

This study examined the effect of African walnut protein isolate, wheat and yellow maize flours on the general acceptability of cookie production. In this study, blends of African walnut protein isolate, wheat and yellow maize flours were studied in a completely randomized design assessment of the proximate composition. The variables were wheat flour (30-50%), yellow maize flour (20-30%) and African walnut protein isolate (10-20%) to generate 20 composite blends. The proximate composition and functional properties of blends and flours were determined using standard methods. Three blends of samples 50.00 g wheat flour, 30.00 g yellow maize flour, 20.00 g African walnut protein isolate; 45.24 g wheat flour, 28.27 g yellow maize flour, 26.48 g African walnut protein isolate and 45.24 g wheat flour, 37.79 g yellow maize flour and 16.97 g African walnut protein isolate as assessed by the highest protein and fiber and low fat contents, were selected from optimization results of proximate composition for production and sensory evaluation of cookies. The proximate composition of flours revealed that African walnut protein isolate was significantly higher in protein than other flours. Fat in African walnut protein isolate was the least, while crude fiber and carbohydrate contents were not detected in African walnut protein isolate. Functional analysis revealed that yellow maize flour had the highest value in water absorption capacity; yellow maize flour and African walnut protein isolate had the highest oil absorption capacity, while African walnut protein isolate scored the least in bulk density. The sample 45.24 g wheat flour, 28.27 g yellow maize flour and 26.48 g African walnut protein isolate had the highest protein and ash, with the lowest fat content among the blends. However, cookie prepared from sample 45.24 g wheat flour, 37.79 g yellow maize flour and 16.97 g African walnut protein isolate had the best overall acceptability. However, the study recommends the flour proportion of sample 45.24 g wheat flour, 37.79 g yellow maize flour and 16.97 g African walnut protein isolate in cookie production by establishing the inclusion in Nigerian food industry and as a way of reducing or alleviate malnutrition.

Modeling of thin layer drying characteristics of blanch-assisted water yam (Dioscorea alata) slices

The thin layer drying characteristics of blanch-assisted water yam slices were investigated with respect to its un-blanched water yam slices in a convective hot air oven. The yam slices (diameter 4 cm; thickness 0.8 cm) were dried at temperatures 50, 60 and 70 °C, respectively with a constant air velocity of 0.13 m/s. The drying data obtained were fitted into six existing drying models: Page, Newton, Midilli, Henderson and Pabis, Logarithmic and Diffusion model. Non-linear regression analysis was used to determine the model parameters; the coefficient of determination (R2) and standard error of estimates (SEE) in order to determine the model best fit. The study showed that the drying process occurred in the falling rate drying period. The blanch-assisted slices had a faster drying rate than the un-blanched yam slices. Among the models, the diffusion model gave the overall best fit for the drying data obtained. The effective moisture diffusivity ranged from 3.18×10-8 to 4.47×10-8 m2/s for the blanch-assisted slices and from 4.73×10-8 to 7.33×10-8 m2/s for the un-blanched slices. The activation energies of the blanch-assisted and un-blanched yam slices were 15.5 kJ/mol and 20.1 kJ/mol, respectively. These processing conditions obtained for water yam flour would be suitable for its process design and control thereby enhancing its utilization and overall acceptability.

Evaluation of vegetable milk from milk blends of soybean (Glycine max.) and African breadfruit seeds (Treculia africana)

Breadfruit milk (BM) is an unpopular nutritive drink compared to soymilk and ia mostly consumed along with the seeds when boiled. Blending with soymilk will give a novel functional drink with enhanced nutritive value to prevent hidden hunger, enhance stability and may popularize the blend. Soymilk and BM from soaked and boiled dehulled African breadfruit were blended in 95:5%, 90:10% and 50:50% ratios, respectively, while 100% soymilk and 100% BM served as controls. Proximate, vitamin, mineral, anti-nutrient and physicochemical analyses were conducted on the milk blends using standard methods. Sensory properties were determined by subjective evaluation with semi-trained panellists. With increasing BM inclusion, proximate composition revealed increase in moisture content (93.60 to 94.05%) and carbohydrate (0.3 to 0.93%) while total solids (TS) (6.40 to 5.95%), ash (0.55 to 0.49%), fat (2.70 to1.85%) and protein (2.93 to 2.70%) decreased. Vitamin A (0.62 to 1.48 µg/100 mL) increased while vitamin B1 (0.12 to 0.08 mg/100 mL) and vitamin C (4.05 to 3.21 mg/100 mL) decreased. Calcium (0.59 to 0.53 mg/100 mL), phosphorus (8.05 to 7.33 mg/100 mL), zinc (0.75 to 0.63 mg/100 mL) and iron (0.59 to 0.54 mg/100 mL) decreased. Flavonoid (0.15 to 0.09 mg/100 mL), saponin (0.13 to 0.9 mg/100 mL), tannin (0.39 to o.29 mg/100 mL), phytate (0.23 to 0.17 mg/100 mL) and oxalate (0.27 to 0.19 mg/100 mL) decreased. Titratable acidity (TTA) (0.23 to 0.26) and visible coagulation time (VCT) (15 to 19 days) increased while pH (6.33 to 5.59), and viscosity (0.48 to 0.45 mPa) decreased. General acceptability (7.01 to 6.41) decreased. The nutrient contents of all the milk blends varied due to increasing concentration effects of the ash, but were acceptable to the panellists mostly at lower levels.

Influence of Substituting Sucrose with Date Palm Fruit Flour (DPFF) on the Nutritional and Organoleptic Properties of Bread

The influence of substituting sucrose with date palm fruit flour (DPFF) on the nutritional and sensory attributes in bread production was studied. Bread was baked in varying proportions of sucrose and date palm fruit flour as follows: (100% sucrose: 0% DPFF), (50% sucrose: 50% DPFF) and (0% sucrose: 100% DPFF). The results of proximate analysis showed that (100% sucrose: 0% DPFF) had 61.90% carbohydrate and fat (3.73%) contents significantly (p<0.05) higher than (50% sucrose: 50% DPFF) and (0% sucrose: 100% DPFF). The protein, ash and fiber contents of (0% sucrose: 100% DPFF) were 6.27, 3.67 and 2.03% higher (p<0.05) than (100% sucrose: 0% DPFF) and (50% sucrose: 50% DPFF), respectively. Result of mineral composition showed that (0% sucrose: 100% DPFF) scored highest in calcium, phosphorus, iron, zinc, copper and selenium while (100% sucrose: 0% DPFF) had least value with the exception of zinc and selenium where (100% sucrose: 0% DPFF) and (50% sucrose: 50% DPFF) have the same values (0.10 and 0.01 mg/100 g), respectively and not significantly different from one another. General acceptability was highest for (100% sucrose: 0% DPFF) followed in descending order by (0% sucrose: 100% DPFF) and (50% sucrose: 50% DPFF). However, the study recommend (0% sucrose: 100% DPFF) as sweetener for bread production above (100%: 0% sucrose) and (50%: 50% DPFF) because it provides wide range of essential nutrients with many potential health benefits. However, there should be public enlightenment on the nutritional importance of date palm fruit and inclusion of date palm fruit flour in Nigerian diet better than sugar as this will reduce malnutrition, increase employment and boost Nigerian economy.

Estimation of nutritional energy values, mineral ratio and mineral safety index in the Royal spiny lobster, Panulirus regius (De Brito Capello, 1864)

Royal spiny lobster is a marine crustacean with a significant economic value as a popular consumer product. However, information on the energy-providing nutrients of lobster is scarce, especially on those living in the southern coast of Nigeria. This study provides information about the nutritional quality and metabolizable energy of flesh and shell of the Royal spiny lobster, Panulirus regius. Proximate and mineral compositions were analyzed, while energy contributions, mineral ratio and mineral safety index were estimated. Higher concentrations of moisture, crude protein and fat were recorded in flesh, while crude fibre, total ash, and nitrogen free extract were more in shell. The proximate with the highest values were crude protein (57.71 g100g-1) and total ash (40.67 g100g-1) in flesh and shell samples, respectively. The flesh had higher total metabolisable energy (1375 kJ 100g-1) and utilizable energy due to protein (38.62). The minerals, with the exception of Na, were concentrated more in the shell. In the flesh sample, Na/K and Na/Mg ratios were within the acceptable ideal range of 1.4 – 3.4 and 2 – 6, respectively, while other ratios were below ideal range. In shell samples, Ca/K (3.55) was within the ideal range of 2.2 – 6.2, while Ca/P (5.23) was higher than the reference balance of 2.6. Mg in shell sample was the only mineral whose safety index value (21.85) was higher than the table value (15) with negative difference (-6.85). K, P and Na showed negative relationships with all the proximate compositions except for the moisture and protein in shell sample, while only K showed positive relationships with moisture (???? = 0.68), protein (???? = 0.63), fat (???? = 0.64) and nitrogen free extract (???? = 0.17) in the flesh sample. The flesh and shell of the lobster will be good alternative sources of nutrients in human diet and animal feed, respectively.