No abstract

The effect of ingestion of microwaved foods on serum antioxidant enzymes and vitamins in albino rats was investigated. In the study, thirty two (32) male wistar albino rats were obtained and grouped into four groups (A, B, C and D) of eight animals each. The animals were acclimatized for 7 days on commercial rat feed. The animals in groups B, C and D were all fed ad libitum with porridge yam, porridge beans and jellof rice with meat/fish reheated for 2 min, 4 min and 6 min for groups B, C and D respectively for 42 days. Group A was fed with un-microwaved food and water for the duration of the study (42 days) and served as control. Antioxidant enzymes superoxide dismutase (SOD), Catalase (CAT) activities, vitamins A and E concentrations were determined using standard methods. Result obtained from the study showed that microwaved food consumption resulted in a significant (P < 0.05) decrease in SOD and CAT activity in rats fed with the microwaved food. Furthermore, antioxidant enzyme activity were more significantly (P < 0.05) reduced in rats exposed to food microwaved for 6 min compared to the control group (A). Also, serum vitamins A and E concentrations were significantly (P < 0.05) decreased in rats fed with food exposed to microwaves for 6 min as compared to the control group. Microwaves and increased microwaving time resulted to a significant reduction in SOD, CAT, vitamin A and E in fed rats. Therefore our study demonstrated that consumption of microwaved foods resulted in a significant decrease in antioxidant protection and may be implicated in the pathogenesis of oxidative stress and degenerative diseases.

The study compared the antimicrobial activities of essential oils (EOs) from Piper guineense (Uziza) and Xylopica aethiopica (Uda) using diffusion and dilution assays, and evaluated their antioxidant properties at different temperatures. Comparison of the antimicrobial activities was determined using well-in-agar diffusion, disc diffusion and broth dilution methods against Escherichia coli, Salmonella sp and Bacillus cereus as test isolates. The antioxidant activities at different temperatures (28, 50 and 70°C) were determined using 1,1-diphenyl-2-picrylhydrazyl (DPPH), ferric ion reducing antioxidant power (FRAP) and Fe 2+ chelation methods. Their antimicrobial activities increased with increase in concentration. From the diffusion assays, B. cereus was more susceptible to the EOs than other isolates (19.5 and 18.0 mm). MIC values obtained from the broth dilution assay (8.0-16.0 mg/mL) were generally much lower than those obtained from disc diffusion and well-in-agar diffusion assays. Percent inhibition of isolates using broth dilution method ranged from 91.28 to 96.86%. Their antioxidant activities decreased with increase in temperature. P. guineense EO yielded higher DPPH scavenging activity (43.25, 46.64 and 33.36%, respectively) and Fe 2+ chelating ability (25.60, 12.58 and 8.97 mg/g, respectively) at the different temperatures, while FRAP elicited the strongest antioxidant ability of the EOs (70.10, 37.51 and 26.55 mg/g, respectively). The EOs exhibited their strongest antioxidant abilities at 28°C.

The effects of regular intake of green tea on nutrient absorption, serum albumin and organ sizes were evaluated on alloxan-induced diabetic rats.. The rats were grouped into five treatment groups: NC (non-diabetic group fed with rat feed and water only), DC (diabetic group fed with rat feed and water only), CON1 (diabetic group fed with rat feed and 1g/100ml of brewed tea only), CON2 (diabetic group fed with rat feed and 2g/100ml of brewed tea only) and CON3 (diabetic group fed with rat feed and 3g/100ml of brewed tea only). Feed, water and tea were provided ad libitum for the respective groups for a period of 21days. At the end of the treatment period, the apparent protein, calcium, iron and magnesium absorption of the groups were determined. The serum albumin as well as visual examination and measurement of organ sizes were also evaluated. The results showed that the diabetic groups CON1, CON2 and CON3 that took different concentrations of the green tea, did not show any significant change (P<0.05) in protein, iron and calcium absorption but had significant reduction (P<0.05) in magnesium absorption and serum albumin level when compared with the diabetic group DC that did not take the tea. There were also no significant change (P<0.05) between the organ sizes of the groups (CON1, CON2 and CON3) and that of group DC.

This work studied the effect of different proportions of ascorbic acid on the physical and proximate properties on wheat-acha composite bread. Bread was produced from wheat (Triticum aestivum) and acha (Digitaria exilis) composite flours. The wheat: acha ratios used were 100:0, 90:10 and 80:20. The proximate, and functional properties of the flours were analysed. The dough improver, ascorbic acid was added at 80, 100 and 120ppm during the bread making process and the proximate, physical and sensory properties of the bread was analysed. Flour sample with 20% acha had the significantly highest values for bulk density (0.744g/cm3), water absorption capacity (1.5g/g), oil absorption capacity (1.564g/g), foam capacity (11.32%) and swelling index (1.24). There was no significant difference in the crude fat and ash content of all bread samples. Significant difference was observed in the volume and specific volume of the bread samples, with 100% wheat flour giving the highest values of 431.33 ml and 3.16 ml/g respectively. However, addition of ascorbic acid significantly improved these parameters with no significant difference between the 100ppm and 120ppm bread samples.  Also the bread samples produced with 100:0 and 90:10 wheat: acha flours showed no significant difference in their sensory properties. The 80:20 composite bread gave significantly lower sensory scores for all the sensory parameters.