The changing aspects of energy and its high demand during convective drying of food products prompted this present study, which aims at investigating the impact of product geometric shapes and process parameters on the energy demand of vegetables during convective drying. It considered three distinctive shapes (sphere, S g ; cylinder, C g ; and slab, R g ) of vegetables (cucumber, garden egg, and white carrot) at constant sample volume, dried in a laboratory convective dryer. The Box-Behnken Design tool was used to design the experiment and explored the effects of material geometries at varying drying conditions (air temperature: 50, 60, and 70 C; air velocity: 1.0, 1.5, and 2.0 ms −1 ) on the total and specific drying energy demand, drying efficiency, percent product shrinkage, and drying time of the fresh vegetables. Results obtained revealed that the spherical-shaped samples exhibited high moisture diffusion and gross reduction in drying time (120 min), thus greater potential for energy and drying system improvement. The values of the effective moisture diffusion, D e (0.72 × 10 −10 ≤D e ≤ 2.13 × 10 −9 m 2 s −1 ) increased with drying temperature, and the maximum D e -value was obtained for the S g -carrot sample. The percent product shrinkage ranged between 78.66-94.73% for the C g -garden egg and S g -cucumber samples, respectively. The specific energy demand of the fresh cucumber, eggplant, and white carrot samples varied significantly (p >.005) with sample geometry. The maximum specific energy demand (16.38 ± 0.41 MJ/kgH 2 O, respectively) was obtained for the cylindrical shaped samples, whereas the minimum specific energy demand of 9.06 ± 0.24 MJ/kgH 2 O was yielded by the spherical shaped samples. The mean energy and drying efficiencies of the system ranged from 3.25 to 12.26% and 7.22 to 28.24%, respectively; whilst drying time ranged between 470 and 840 min.At the optimum process variables of 69.85 C, 1.22 ms −1 , 0.999 geometric shape, and −0.9977 crop sample, the specific energy demand, drying time, drying efficiency, and percent shrinkage were found to be 14.21 ± 0.84 MJkg −1 , 820 ± 9.00 min, 22.76 ± 0.74%, and 92.104 ± 1.00%, respectively. Prospects for future application and recommendations for further studies were suggested.

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The microbiological properties of stored freeze dried cow milk cheese and soy cheese were investigated. Cow milk cheese and soy milk cheese were prepared using appropriate standard procedures. The microbial qualities of the stored freeze dried samples were determined using standard  methods as prescribed by Compendium of Methods for the Microbiological Examination of Foods and Bacteriological Analytical Manual. Data obtained were analyzed statistically to determine the effect of the packaging materials and storage duration on the microbial qualities of freeze dried cheese samples. Result of the microbial composition for the fresh cow milk and soy cheese for bacterial and fungi count are 3.00x103±0.01, 2.54x106±0.05 and 2.76x103±0.02, 2.60x106±0.10 while the result for the freeze dried cow milk and soy cheese before storage are 2.72x103±0.02, 2.35x106±0.30 and 2.54x103±0.03, 2.38x106±0.50. This indicates that all the packaging material types used have the ability to minimize the microbial growth of stored freeze dried cheese. Polythene film is recommended to be more suitable in terms of cost, availability, compactibility and weight. Keywords: cheese, freeze drying, microbial qualities, packaging materials.

This study investigates the quality composition of Aba knife fish (Gymnarchus Niloticus) predominant in South-eastern Nigeria. The fish sample require proper processing techniques to preserve their organoleptic qualities for a substantial period. The objective of the study was to investigate the influence of oven-drying process on the proximate and organoleptic qualities of Gymnaruchus Niloticus. The studied fresh fish fillets were rinsed in clean water, brined and spread in trays before taken for oven drying. An oven drier (FALC STF-F-52) was used for the oven-drying process. Analyses of proximate compositions (moisture content, crude lipid, crude protein, ash content and crude fiber) were carried out on the fresh and oven dried fish samples. The study showed that oven drying decreases the moisture content to a safe level of 38.13 ± 0.01% dry basis(d.b), and increase the crude protein content (18.23±0.01), fat content (4.34±0.01), ash content (3.40±0.01), carbohydrate content (35.96±0.01) of the investigated fish samples. There were no crude fibre contents (0.00) in the fresh fish samples. Therefore, the oven drying process had no noticeable effect on the fibre content. The oven dried fish samples were rated high in terms of taste, aroma, colour, texture and general acceptability by the panel of assessors. The significance of the obtained results as well as recommendations for further studies were offered.

The effect of freeze drying on the qualities of fresh cow milk and soy milk cheeses was investigated, with a view to preserve and present them in a more stable and portable form. The cow milk cheese and soy milk cheese used were freshly prepared with dimension of 2 x 3 cm and 0.2 cm thickness. The cow milk and soy cheese were divided into 6 portions of 100 g each. The initial properties of the cheeses samples been determined using a portion of 100 g each, the remaining 500 g were freeze dried. The nutritional, microbial and sensory qualities of the freeze dried cheeses were determined using standard methods. Results showed that freshly prepared cow milk cheese contains 54.02% moisture, 20.34% protein, 6.40% ash, 18.11% fat and 4.25% carbohydrate, 3.52mg/100g sodium, 7.02mg/100g potassium, 5.22mg/100g magnesium, 6.32mg/100g iron, 11.12mg/100g calcium, 3x103 cfu/g bacteria and 2.54 x 106 cfu/g fungi whereas freshly prepared soy cheese contains 50.89% moisture, 22.05% protein, 6.31% Ash, 19.02% fat and 4.06% carbohydrate, 3.52mg/100g sodium, 7.04mg/100g potassium, 5.14mg/100g magnesium, 6.20mg/100g iron, 10.76mg/100g calcium, 2.76x103 cfu/g bacteria and 2.60 x 106 cfu/g fungi. The moisture and fat contents of the freeze dried cow milk and soybean milk decreased significantly (P < 0.05) from 54.02% to 4.28%, 18.11% to 4.05% and 50.89% to 4.19%, 19.02% to 4.30% respectively. Freeze drying significantly decreased the bacteria and fungi contents of fresh cheeses; it decreased from 3x103 cfu/g to 2.72 x 103 cfu/g, 2.54 x 106 cfu/g to 2.35 x 106 cfu/g, and 2.76 x 103 cfu/g to 2.54 x 103 cfu/g, 2.60 x 106 cfu/g to 2.38 x 106 cfu/g for cow milk and soy milk cheese respectively. The carbohydrate, protein, ash content, calcium, sodium, magnesium, taste, appearance, flavour, acceptability of the cow milk cheeses increased significantly (P < 0.05) when freeze dried. Decreases in moisture content, fat and microbial counts of cheeses would enhance its stability and shelf life if properly packaged.