Research
Identification of Appropriate Sample and Culture Method for the Isolation of Thermophilic Bacteria from Automobile Radiators
The purpose of this study was to identify appropriate samples and culture techniques on the isolation of thermophiles from automobile radiators. Water samples from these artificial environments were used for the isolation of thermophilic bacteria at 60°C and pH 7.65. Samples from Honda, Jetta and Passat (automobile vehicles) were screened for the growth of thermophilic organisms using nutrient broth medium and their turbidity were measured using spectrophotometer at 600nm. Results of this study suggest that optimal isolation rates of thermophiles from automobile radiator samples were achieved by culturing the sample on nutrient broth and agar at high temperature. Extremophilic microorganisms, especially thermophilic bacteria can facilitate the enzymatic degradation of polymeric substrates such as starch, cellulose, xylan, pectin and chitin.
Levels of Aflatoxins in Some Agricultural Commodities Sold at Baboko Market in Ilorin, Nigeria
This study was carried out to investigate the levels of aflatoxins in some agricultural commodities sold at Baboko market in Ilorin. The agricultural commodities were grains, root and tuber products, onions, cray-fish and stock-fish. Aflatoxin B1 (AFB1) in grains ranged between 2.57±0.61 in wheat and 21.72±2.92 ppb in sorghum, while AFB2 ranged between 0.46±0.23 and 6.66±2.11 ppb in all the samples investigated. Varying levels of AFB2, AFG1 and AFG2 were detected in grain samples. AFB1concentrations in root and tuber were: 5.66±1.69 ppb in yam chips and 4.20±0.90 ppb in cassava chips, whereas AFB2 was observed to be 2.97±1.69 and 1.58±0.30 ppb respectively. AFG1 concentration in yam chips was 3.52±0.24 ppb while that of cassava chips was 4.80±0.31ppb. Cumulative higher levels of aflatoxins B were observed for onion samples when compared to aflatoxin G. It was generally observed that stock-fish had higher levels of aflatoxins when compared to cray-fish with exception of AFG2 in cray-fish which was higher than that of stock-fish.
Effects of Edible Coatings from Aloe Vera Gel on Quality and Postharvest Physiology of Ananas Comosus (L.) Fruit During Ambient Storage
Pineapple (Ananas comosus (L.) Merr.) is an important fruit crop grown in Nigeria. Extension of the shelf life of pineapple fruits continues to be a challenge in Nigeria. The search for safe, healthy and environmental friendly treatments has led to increased interest in research into edible and biodegradable films and coatings. The aim of this study was to evaluate the effect of Aloe vera gel as an edible coating on weight loss, ascorbic acid, pH and firmness in order to extend the shelf-life of pineapple stored at ambient temperature of (27+2oC) and relative humidity of 55-60% for seven weeks. The above parameters which are related to post -harvest quality loss were however significantly controlled in the pineapple coated with A. vera gel. The storability of pineapple fruits was extended by seven weeks. It was concluded that A. vera gel used as a coating for pineapple could serve as an alternative to post - harvest chemical treatments.
Quality and Safety of Citrus Sinensis Coated with Hydroxypropylmethylcellulose Edible Coatings…
Edible coatings based on hydroxypropylmethyl-cellulose(HPMC) with and without an aqueous extract of Moringa leaves, were developed and applied to orange, in order to improve quality and shelf life during storage, while taking advantage of the beneficial health properties of Moringa. Weight loss, firmness and ascorbic acid content of uncoated and coated samples were determined throughout ambient storage. The two experimental coatings were: HPMC without crude extract of Moringa oleifera and HPMCME mixed with 75mg/ml of crude extract of Moringa oleifera . Four hundred and eighty (480) orange fruits were stored for seven weeks at ambient temperature of 27±3oC and relative humidity of 50- 65%. The overall result showed that polysaccharides coating from (HPMC) and (HPMCME) is effective in extending the shelf-life of orange fruits when compared to untreated in the following order:(HPMCME) > (HPMC) >Control.
