Food Science and Technology

Cashew (Anacardium occidentale L.) apple juice was produced and pasteurized at 80°C for 15 min in a water bath. The juice was packaged in different packaging materials -green (G), brown (B), white (W) bottles and polyethylene sachet (S) in 200ml batches and stored for four months at room (28°C) and refrigeration (4°C) temperatures to study the effect of packaging materials on the colour and sensory qualities of cashew-apple juice (CAJ). There were significant differences (p<0.05) in the values for colour (5.6 -8.3 EBC) of the juice stored at 28°C as compared with those stored at 4°C. Samples B and G retained more colour (7.0 and 7.2 EBC) at refrigeration temperature when compared with samples W and S. Sensory qualities (colour and general acceptability) of CAJ stored with various packaging materials was significantly affected while taste and flavour of CAJ packaged with G and B samples were not significantly affected at the room temperature up to the fourth month. At 4°C, there was no significant difference (p>0.05) in all the sensory qualities of CAJ between the first two months in all the packaging materials studied. At third and fourth months, samples W and S was significantly affected while there was no significant effect between G and B samples at these months. Therefore, CAJ can conveniently be produced and stored in green and brown bottles for up to four months in the refrigeration temperature to retain its colour and sensory qualities. CAJ could also be stored in polyethylene sachet but not more than two months while the fruits are in season to serve as a cheap source of fresh drink and to reduce the 90% wastage of cashew-apples in the orchard.

Defatted and undefatted cashew (Anacardium occidentale Linn.) kernel flours were produced and the effect of defatting on the proximate, mineral and functional properties was determined. It was ascertained that the proximate content of protein, crude fibre and carbohydrate (34.0, 6.2 and 32.2%, respectively) increased significantly in the defatted compared to undefatted cashew kernel flour. A decrease was observed in the moisture content, ether extract (crude fat) and total ash (4.4, 1.6 and 1.8%, respectively) of the defatted flour. There was significant difference (p<0.05) in all the analysed mineral elements between the defatted and the undefatted flours except manganese with significantly higher (p<0.05) value in the undefatted compared to the defatted sample (9.0 and 2.9mg/100g), respectively. There was no significant difference (p>0.05) in the bulk density, foam capacity/stability, emulsion capacity and nitrogen solubility at pH8.0 of the defatted and undefatted cashew kernel flours. A significant difference was observed between these two samples in the water/fat absorption capacity, emulsion stability and nitrogen solubility at pH8.0. The results obtained in this study indicate that defatted cashew kernel flour is a good source of protein and can be used to substitute wheat flour in snack production and formulation of children's meals to reduce the importation of wheat flour into Nigeria. It can also be a useful source of low-fat fabricated foods as well as animal feeds.

Abstract: Cashew apple (Anacardium occidentale L.) juice was produced and pasteurized at 80oC for 15 min in a water bath. The juice was packaged in different packaging materials – green (G), brown (B), white (W) bottles and polyethylene sachet (S) in 200ml batches and stored for four months at room (30±1oC) and refrigeration (4oC) temperatures to study the effect of packaging materials on the vitamin C and pH of cashew-apple juice (CAJ). There were significant differences (p<0.05) in the value of vitamin C (48mg/100ml – 159mg/100ml) and pH (5.0 – 6.2) of the juice stored at 30±1oC as compared with those stored at 4oC.At the ambient temperature, the highest loss of Vitamin C was observed with samples S which ranged from (83 – 48), first to fourth month, respectively. This is still higher than 45mg daily adult recommendation. The colour of the bottles did not have significant effect on the loss of vitamin C as the values ranged between 169 – 128mg/100g (W), 187 – 130mg/100g (G) and 188 – 132mg/100g (B) for months one to four at refrigeration temperature. Samples B and G retained the pH value of the juice at refrigeration temperature compared with samples W and S. Though significant reductions was observed in the values of Vitamin C as time of storage progressed, the retained values in this study were still high when compared with the vitamin C content of other fruits in their fresh state. Therefore, CAJ can conveniently be produced and stored in green and brown bottles for up to four months in the refrigeration temperature to retain its vitamin C content and pH value which is an indication of good quality product. CAJ could also be stored in polyethylene sachet but not more than two months while the fruits are in season to serve as a cheap source of fresh drink, vitamin C and to reduce the 90% wastage of cashew-apples in the orchard.

Moringa oleifera leaf powder was processed using oven, sun and shade drying techniques to study the effect of drying on the proximate and mineral properties. Chin-chin was enriched with 1% dried Moringa leaf (DML) powder samples. Chin-chin without Moringa enrichment was equally produced and used as the control sample. Proximate analysis of the DML powder samples showed that oven drying technique effectively decrease the moisture and fat contents of the powder to 1.65% and 9.12%, respectively and increased the fibre value to 6.34%. The highest protein value (32.14%) was observed on the sun dried sample and there was significant difference (p<0.05) in all the DML powder samples. Mineral content of the DML powder showed that there was no significant effect (p<0.05) in the magnesium content of the samples while there was in the calcium, iron and zinc contents. Oven dried sample had the highest calcium (190.5mg/100g), sun dried highest zinc (7.1mg/100g) and shade dried highest iron content of 51.3mg/100g. Proximate composition of the produced chin-chin samples showed that shade dried had significantly lower moisture (2.5%), highest protein (11.21%) and fibre (2.56%) compared to other chin-chin samples. Apart from ash content of the chin-chin samples, a significant effect was observed in all the proximate composition of the products. Sensory evaluation of the DML powder enriched chin-chin showed that there was no significant effect in all the sensory attributes analysed. Control chin-chin sample (A) had significantly higher likeness in all the organoleptic attributes. For the fact that general acceptability score of Moringa enriched chin-chin ranged between 7.1 – 7.2 on a 9 point hedonic scale, is an indication that they were equally accepted by the panelists.

Beetroot (Beta vulgaris) tubers were processed into juice and treated with 0, 5, 10, 15 and 20% sugar syrup and pasteurized at 85°C for 10min to determine the level that will make a positive impact on the sensory attributes. The result showed that increasing levels of sugar syrup in the treated beetroot juices enhanced the sensory attribute of color; flavor and general acceptability up to 20% while sensory attribute of taste got to its peak at 15% sugar concentration and they were significantly higher than the control sample. Twenty percent (20%) sugar syrup was further used with lemon (30%), ginger (0, 2, 4 and 6%), ehuru (Mondora myristica) (0, 2, 4 and 6%) and a blend of ginger and ehuru (1:1) in the treatment of beetroot juice samples labelled A – H to study the effect of these treatments on the physical and sensory properties. The result showed that viscosity ranged between 0.065 – 0.100pa.S (E and D samples), pH 4.47 – 6.45 for samples D and A, sugar content 19.30 – 20.00% (D and multiples of A, F and G samples), total solid 19.82 – 21.65% for A and D samples, respectively. Sensory result of beetroot juice samples treated with indigenous spices showed that 4% ginger and 2% " ehuru " successfully improved all the sensory attributes more than the control sample.

Mixed fruit juices were produced from the blends of orange (Citrus cinensis) and pineapple (Ananas comosus) fruit and pasteurized at 80°C for 10 min. Packaged mixed fruit juice was purchased from the open market and used as a reference sample to study the physical, chemical and sensory properties of the juices. The physical properties studied included pH, titratable acidity, total sugar and total solid with value ranges of 3.50 – 3.97, 0.47 – 1.27%, 10.20 – 14.88% and 11.75 – 17.53%, respectively. Chemical composition of the juice blends and the reference sample showed moisture content with a range of 82.48 – 88.35% (E and F samples), crude protein 0.81 – 1.17% (samples B and A), ash 0.42 – 2.68% for samples F and A, carbohydrate 8.16 – 16.19% (A and E samples) and vitamin C with a range of 33.45 – 66.55mg/100g for samples E and A, respectively. Sensory evaluation result showed a significant difference (p<0.05) in the attributes of colour, flavour, taste and overall acceptability of the orange/pineapple juice blends compared to the reference sample. This indicates that homemade fruit juices were more acceptable than the packaged mixed fruit juices already in existence in the market. Though the values for pH and titratable acidity occurred in a reversed case which showed that these juices have the advantage of being stored for a long time, there is need to carry out further investigation to determine its shelf-life stability.

Two hundred and ten (210) structured questionnaires which comprised three sections (A, B and C) were distributed to selected fast food/restaurants in G.R.A Phase II, Rumuogba and Trans-Amadi Industrial Layout. A 4-point Likert scale was used to score the customers’ food preferences and factors that influence food preferences. The sample population was chosen at random. One hundred and ninety one (191) respondents were collected back and analysed in simple percentage and bar chart. Section A (demographic characteristics) showed that customers who were identified to patronize fast food/restaurants most frequently were male (66.0%), those between ages of 31 – 40 (64.4%), B.Sc. degree holders and married people (78.5% and 83.8%), respectively and finally 70.7% customers dine outside their homes more frequently during lunch period. Section B presented different kinds of dishes prepared at fast food/restaurants. Among all the dishes, the result showed that vegetable soup, gari, fried chicken, fried rice and supreme ice-cream were highly preferred by 90% fast food/restaurant’s customers each. Dishes such as; assorted meat, tilipia fish, isie-ewu, cow tail pepper soup (3% each) and ogbono soup, banga soup, amala and goat meat (2% each) were rated not preferred by the fast food/restaurant customers. Section C depicted factors that influence customers’ food preference such as restaurant environment (90%) with the highest respondent who perceived it as the most important factor. The least was food quality rated by 40% customers as the factor that influences their dining experience.

The study was undertaken to determine the effect of drying methods on the physicochemical and sensory properties of wheat flour cookies produced with Moringa powder fortification. Cookies were produced with Moringa leaf powder derived from various drying methods (shade drying, sun drying and oven drying) and fresh leaves prior to milling and used in the formulations. The physical properties, proximate compositions and sensory attributes of the cookies were analysed. The results showed significant differences in weight of all the cookie samples from various drying methods while there was no significant difference in the fresh leaves and control cookie samples. Oven dried sample was the least in height (0.67), higher in diameter (3.80) and spread ratio (5.79) compared to other drying methods studied. All Moringa supplemented cookies had significantly lower (P<0.05) ash and fat contents than the control sample with ash and fat content of (2.06mg/100g and 20.32mg/100g), respectively. There was no significant difference between the protein content of the control cookie samples and cookies prepared from various drying methods studied. All the Moringa fortified cookies had significantly (p>0.05) higher fibre compared to the control sample. Sensory scores showed highest acceptability with the control sample (8.30) but there was no significant difference between the general acceptability of shade and sun dried samples (6.95 and 6.70), respectively. The findings suggest preliminary prospects for the development of Moringa fortified cookies for potential nutritional health benefits.

Cashew (Anacardium occidentale L.) apple juice was processed using pasteurized apple (PA), pressure treated apple (PTA), gelatine treated apple (GTA), carbonate treated apple (CTA), salt treated apple (STA), hot water treated apple (HWTA) and unpasteurized apple (UPA) was used as the control sample. Cashew kernels were also processed using oil frying and oven drying techniques and the imported cashew kernel served as the control. The effect of these treatments and techniques on the physical, chemical, tannin and sensory properties were studied. The result of the juice samples showed pH range of 4.06 – 7.28 (HWTA and CTA), colour 3.08EBC – 7.50EBC (CTA and GTA), total solid 12.76 – 24.83% (PA and GTA), titratable acidity 0.03 – 1.97% (CTA and STA), crude protein 0.22 – 8.52% (STA, HWTA and GTA), ash 0.24 – 3.72% (STA and CTA), carbohydrate 6.17 – 8.62% (GTA and STA) and tannin 0.07 – 2.84mg/100ml (HWTA and PA), respectively. Hot water treatment significantly reduced the tannin content of the juice by 96.20%. HWTA juice was observed to maintain significantly high (p<0.05) sensory attributes of colour, taste, flavour, desirability and general acceptability (4.65, 4.21, 3.60, 4.27 and 4.73, respectively) and effectively reduced the astringency of the juice with the score of 2.53. Oil frying and oven drying techniques significantly did not affect all the chemical properties of the produced cashew kernel compare to the imported sample. The reduction of tannin in the cashew kernel was achieved using oil frying technique as regards to the imported sample by 0.1%. There was no significant difference (p<0.05) in all the sensory attributes between the oil fried and imported cashew kernels. From the analysis, the reduction of tannin content in cashew apple juice and cashew kernel was achieved by immersing the apple in hot water before juice expression and by frying the kernels in hot oil before the remover of tasta, respectively and still maintain the physical, chemical and sensory properties of the products.

One kilogram of five brands of commonly used iodized salts such as Dangote (DT), Mr Chef (MC), Magic Time (MT), Anapuna (AP) and Uncle Palm (UP) salt were procured from local market (LMT) and supermarket (SMT). They were stored at a temperature of 28±2 o C for a period of six weeks and analysed to determine iodine loss over storage time. Iodine values at week 0 were used as the standard. The result showed that at week 0, salt samples had iodine content of 27.49 ppm, 39.65, 47.05, 47.60 and 92.55 ppm for UP, AP, MC, DT and MT, respectively for LMT salts with significantly lower (P < 0.05) value in AP and higher value in MT salts. Same LMT salts had moisture content of 1.72% UP, 1.09% AP, 0.71% DT, 0.53% MT and 0.46% for MC. SMT salts had significantly higher and lower iodine values of 94.15 and 31.15ppm (MT and UP), respectively. AP had 48.08 ppm, MC 49.70 ppm while DT had 51.25 ppm of iodine values. Moisture values recorded to be 2.07%, 1.13, 1.11, 0.61 and 0.46% for UP, DT, AP, MT and MC, respectively for SMT salts. During storage, iodine values of salt samples from the LMT were observed to decrease from 47.55 – 45.25 ppm with loss of 5.60% for DT salt, 47.05 – 41.05 ppm loss of 14.29% for MC, 92.55 – 84.65 ppm loss of 18.81% for MT, 39.65 – 38.08 ppm loss of 3.74% AP and 27.49 – 18.15ppm loss of 22.24% UP salt. Those from SMT equally decreased from 51.25 – 51.05 ppm loss of 0.48% (DT), 49.70 – 47.55 ppm loss of 5.12% (MC), 94.15 – 91.00ppm loss of 7.50% (MT), 48.05 – 42.50 ppm loss of 13.21% (AP) and 31.15 – 18.55 ppm loss of 30.00% for UP. Among all the salt samples, iodine values of those from SMT were better compare to those from LMT. It is then recommended to store salts away from direct sunlight.

The aim of this study was to produce and evaluate table wine from two different varieties of pawpaw (rose red and yellow
pawpaw). The must was evaluated for physicochemical and microbiological changes during fermentation while the wine was
analyzed for physicochemical characteristics, microbiological quality and sensory properties and compared with commercial grape
wine. Specific gravity of the “must” during fermentation decreased from 1.059-0.995 for rose red pawpaw and 1.005-0.990 for
yellow pawpaw. The sugar content decreased from 13-3% on the 14th day of fermentation for rose red pawpaw while yellow
pawpaw “must” decreased from 12.5-3%. pH drop for the yellow pawpaw “must” was 4.7-3.4 on the 14th day and 4.0-3.4 for rose
red pawpaw “must”. Titratable acidity of the pawpaw “must” increased from 0.16-0.32% for rose red pawpaw “must” and
0.20-0.52% for yellow pawpaw “must”. Microbial analysis of the “must” during fermentation showed that yeast count increased from
no growth to 3.0 × 106 cfu/mL for yellow pawpaw must and 4.0 × 106 cfu/mL for rose red pawpaw, respectively while total bacterial
count decreased from 5.4 × 107-l.5 × 107 cfu/mL for yellow pawpaw must and 5.2 × 107-1.2 × l07 cfu/mL for rose red pawpaw
“must”. Coliform recorded no growth throughout the period of fermentation. Physicochemical analysis of the wine showed that the
yellow pawpaw wine has a specific gravity of 0.999, alcohol content 8.00%, titratable acidity of 0.59%, pH of 3.5 and sugar content
of 3%. The rose red pawpaw wine had sugar content of 3%, titratable acidity of 0.38%, alcohol content 7.69%, specific gravity 0.997
and pH of 3.5. Microbial analysis of the wine showed no growth of coliform and yeast while bacterial count was 1.0 × 106 cfu/mL for
both wines. Sensory results for the pawpaw wine showed no significant (p > 0.05) difference in the clarity and overall acceptability
from the commercial wine.

This study was conducted to evaluate the effect of oven drying on the proximate composition and rehydration characteristics of shellfish. Shellfish studied included rough and smooth periwinkle, oyster and whelk. Proximate composition of the fresh samples were determined. Then dried in the oven to a moisture content of 10% and further rehydrated with distill water in sample water ratio of 1:40 and allowed to equilibrate. Proximate composition of the fresh shellfish showed that moisture content ranged from 82.38 to 69.24% with fresh smooth periwinkle having the highest moisture value while whelk had the lowest. The results also showed that whelk had the highest values for ash (2.92%), crude protein (18.83%) and crude fibre (3.71%) when compared to other samples. On rehydration, a moisture loss of 11.75%, 13.28%, 19.24% and 22.04% were observed for rough periwinkle, smooth periwinkle, oyster and whelk, respectively. The results for rehydration indices revealed that dehydration ratio was significantly (p<0.05) high for whelk (1.44), followed by oyster (1.29), rough periwinkle (1.23) and lastly, smooth periwinkle 1.20. Rehydration ratio of whelk (1.47) was equally significantly higher, followed by oyster (1.33) and the least were rough and smooth periwinkle (1.17). For coefficient of reconstitution, oyster recorded the highest value of 1.03, followed by whelk 1.02, rough periwinkle 0.95 and smooth periwinkle 0.98. Rate of water imbibition revealed a sharp increase in the water content of smooth periwinkle up to 240 min and thereafter, it slowed down until equilibrium was reached. In terms of rough periwinkle, oyster and whelk; water imbibition took place with rehydration time up to 300 min, 210 min and 270 min, respectively, thereafter they slowed down. The results have demonstrated that the rate in which oven drying affect the physical and nutritional qualities of shellfish differs.