Browsing by Author "J. B. Hussein"

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    Effects of Drying Methods on the Chemical Properties of Okra (Abelmoschus esculentus L. Moench) Slices
    (Current Journal of Applied Science and Technology, 2018-10-01) J. B. Hussein; J. O. Y. Ilesanmi; K. B. Filli; M. S. Sanusi
    Okra (Abelmoschus esculentus) samples were subjected to three different drying methods using solar, sun and oven. Chemical and sensory properties of the dried okra samples were investigated using fresh okra as a control. Natural open sun drying took about 191/2 hours to dry the okra to a constant moisture content of 12.67% (w/b), solar dryer took 12 hours to dry to 12.50% (w/b) and hot air oven took about 101/2 hour to dry to 5.50% (w/b). The results of chemical properties showed that the fresh okra contained 75.67% moisture, 11.99 % crude protein, 0.34% crude fat, 1.03% crude ash, 0.50% crude fiber, 10.47% carbohydrate, 92.90 Kcal energy value, 12.83 cP viscosity and26.04 mg/100 g vitamin 'C'. The open sun dried okra contained 21.93% crude protein, 2.56% crude fat, 9.33% crude ash, 8.05% crude fiber, 45.46% carbohydrate, 292.60 Kcal energy value, 13.10 cP viscosity and 17.14 mg/100 g vitamin 'C'. Solar dried okra contained 29.40% crude protein, 4.91 % crude fat, 10.12% crude ash, 8.71% crude fiber 34.36% carbohydrate, 299.23 Kcal energy value, 15.47 cP viscosity and 19.21 mg/100 g vitamin 'C'. Oven dried okra contained 17.97% crude protein, 2.20% crude fat, 9.23% crude ash, 6.12% crude fiber, 58.98% carbohydrate, 333.60 Kcal energy value, 21.13 cP viscosity and 14.08 mg/100 g vitamin 'C'. The above results showed that the drying methods used have a significant effect (p<0.05) on the physicochemical properties of the dried okra. The nutritional and sensory quality of the solar dried okra is superior to open sun and oven dried okra. It was concluded that better quality shelf stable dried okra can be obtained by solar drying method.
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    ENERGY AND EXERGY ANALYSIS DURING THE DEHYDRATION OF PRETREATED SWEET POTATO VIA A CONVENTIONAL AIR DRYER
    (2017-12-02) J. B. Hussein; M. S. Sanusi; M. A. Usman
    The energy and exergy analysis during the dehydration of pretreated sweet potato via a conventional air dryer (Model: DHG-9023A, England) was investigated. Sweet potatoes were sliced and divided into three lots; first lot was pretreated in 0.5% sodium metabisulphite (SMB), second lot was water blanched (WAB) and the last lot was untreated (UNT). The samples were dried at varying drying temperatures (60oC, 70oC and 80oC) and constant air velocity of 1.5 ms-1. Energy utilization (EU), Energy utilization ratio (EUR), heat transfer rate (Qevap), exergy loss and exergy efficiency were estimated using standard equations. The results showed that the higher the temperature, the shorter the drying time irrespective of the treatment. However, WAB sweet potato slices takes longer time to dehydrate than SMB and UNT. The energy analysis showed that EU, EUR and Qevap increases as temperature increased. WAB slices has the highest EU, EUR and Qevap next to it was SMB and UNT had the least values. For exergy analysis, exergy loss and exergy efficiency increases with increased in drying temperatures. Comparing the drying temperatures, the highest and lowest exergy loss was obtained at 80oC and 60oC. The least exergy efficiency was obtained at 60oC, thus, drying at 70oC and pretreatment with SMB gave the most acceptable processing conditions base on effective moderate exergy loss (8.69 KJ/s) and exergy efficiency (0.38). However, it is recommended that process optimization should be done in further studies.