SUSCEPTIBILITY TO BRUCHIDS AMONG COMMON BEANS IN UGANDA

The bean bruchids, Acanthoscelides obtectus Say and Zabrotes subfasciatus Boheman (Coleoptera: Bruchidae), are cosmopolitan pests of stored dry common beans ( Phaseolus vulgaris L. ), causing damage through reduction of grain quality and seed germination. Biological resistance to these bruchids was definitively established in non-cultivated bean accessions, and has been introgressed into a range of drybean market classes. However, existing resistance to bruchids in Uganda’s common bean germplasm has not been systematically studied. In this study, 45 bean genotypes from the National Bean-Breeding Programme (25 genotypes) and agroecologically diverse bean growing areas in Uganda (20 genotypes), were evaluated for postharvest bruchid resistance. None of the evaluated bean genotypes expressed resistance to either bruchid species, with all the 45 bean genotypes supporting bruchid development, reproduction and feeding. All genotypes were severely damaged by bruchids feeding, resulting in significant (P<0.05) reduction of seed germination. Reduction in seed germination was related to the number of emergence holes and seed size; small bean seeds damaged by up to 2 bruchid emergence holes had a 7.1% reduction in germination, while large bean seeds with a similar number of emergence holes showed a 25% reduction in germination. Whereas this study further confirms bruchids as important storage pests of beans causing direct loss through consumption of the seed and indirect loss through viability deterioration, the resistance to bruchids in the evaluated range of Uganda’s dry bean germplasm is inadequate for direct exploitation in a breeding programme.

Viability of probiotic bacteria and some chemical and sensory characteristics in cornelian cherry juice during cold storage

Background: Increased popularity of vegetarianism, lactose intolerance, and the high cholesterol content in dairy products, are all factors that have recently increased the demand for nondairy probiotic products. The objective of this study is to evaluate the effect of refrigeration on the viability of probiotics and asses someof the chemical and sensory characteristics in cornelian cherry juice. Results: The Iranian native probiotic strain (L. casei T4) showed greater viability compared to industrial types (viable count of 8.67 log cfu/mL versus <6.0 log cfu/mL at d 28). However, this most tolerant Iranian strain, could not withstand the conditions of ‘Natural juice’ at pH 2.6 for more than 7 d. Following a pH adjusted treatment (to pH ~3.5), the viability of the strain was improved to 28 d with some evidence of increased growth of the probiotic. However, the level of antioxidant activity, anthocyanin and phenolic compounds, revealed a slight decrease during cold storage. The changes in the chemical profile of the sample containing L. casei T4 indicated fermentation activity during cold storage. Sensory evaluation results showed significant differences between samples containing L. casei TD4 and other samples in taste, odor and overall acceptance in a complimentary way. Conclusions: The results showed that low pH and presence of inhibitor phenolic compounds of cornelian cherry juice have negative effect on viability of probiotics, especially industrial strains during refrigerated storage.

Equilibrium Sorption Studies of Hg (II) Ions from Aqueous Solution using Powdered Swamp Arum ( Lasimorpha senegalensis ) Seeds.

The potential of swamp arum ( Lasimorpha senegalensis ) seeds as a low-cost adsorbent for the removal of Hg (II) ions from aqueous solution was investigated in this study. The influence of initial metal concentration on the percent adsorption of Hg (II) ions onto powdered swamp arum seeds was studied in a batch system and the filtrate was analyzed using Atomic Absorption Spectrometry (AAS). The percent adsorbed for 10, 20, 40, 60 and 80 mg/L of the aqueous solution were 97.7, 98.9, 99.3, 99.7, and 96.5% respectively. Three isotherms; Langmuir, Freundlich, and BET were used to model the equilibrium sorption of Hg (II) ions onto powdered swamp arum seeds, with a correlation coefficient of 0.998, 0.784 and0.842 respectively. The Langmuir model fitted the equilibrium data best, with a correlation coefficient of 0.998 and a maximum adsorption capacity qm, of 5.917 mg/g. Thus, indicating monolayer coverage on the adsorbent. The results showed that swamp arum seed have the potential to be applied as alternative lowcost biosorbent in the remediation of heavy metal contamination in waste water.

NUTRITIONAL AND AMINO ACID ANALYSIS OF RAW, PARTIALLY FERMENTED AND COMPLETELY FERMENTED LOCUST BEAN ( Parkia biglobosa ) SEEDS

The nutritional and amino acid analysis of raw and fermented seeds of Parkia biglobosa were carried out. Parameters investigated include moisture, crude protein, crude fat, ash, crude fibre and mineral contents; and the effect of the degree of fermentation on these parameters was also investigated. The amino acid compositions of all the samples were evaluated and amino acid quality determined by calculating amino acid scores and the predicted protein efficiency ratio (P-PER). Results showed that the proximate composition was significantly affected by fermentation, although there was little difference between the parameters for the partially fermented and completely fermented samples. Based on dry matter percentage, protein content was in the 39.77 – 43.74 % range while crude fibre ranged between 5.55 – 7.42 %. The ash content was lowest in the raw sample (2.34 %), while the fermented samples had ash contents between 4.27 and 8.33 % for the fully fermented and the partially fermented seeds, respectively. The fat content increased from 8.65 % in the raw seed to 24.4 % and 27.6 % for the partially and completely fermented samples, respectively. Results of the amino acid analysis showed that the partially fermented sample had the lowest quantities of all amino acids determined and had lysine as the limiting amino acid, whereas the raw and completely fermented samples had very similar amino acid profile with amino acid scores of 100, indicating that there are no limiting amino acids. All the samples were rich in essential amino acids. The P-PER also showed that the partially fermented sample had the lowest protein efficiency while the raw seed had the highest. Mineral contents generally increased from the raw, through the partially fermented, to the completely fermented seeds and results showed the samples to be good sources of potassium (K), calcium (Ca), manganese (Mn) and copper (Cu) in addition to being complementary sources of other metals. Locust bean seed does not accumulate lead and is, therefore, safe for consumption without the potential of food poisoning.

Effect of Allium sativum (garlic) methanol extract on viability and apoptosis of human leukemic cell lines

Purpose: To investigate the effect of Allium sativum (garlic) methanol extract on viability and apoptosis of human leukemic cells. Methods: Cell viability was determined using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay at concentrations of 3.125, 6.25, 12.5, 25, 50, 100, 200, 400 and 800 ug/mL of Allium sativum extract following 48-h treatment on U-937, Jurkat Clone E6-1 and K-562 cell lines. The mode of cell death was determined by Annexin V-FITC staining and analyzed by flow cytometry. Results: The results show that the half-maximal inhibitory concentration (IC50) of A. sativum on U-937, Jurkat Clone E6-1, K-562 cell lines was 105 ± 2.21, 489 ± 4.51 and 455 ± 3.13 μg/mL, respectively, compared with negative control, while apoptosis was 17.93 ± 0.95 % for U-937 cells (p ≤ 0.05), 38.37 ± 1.88 % for Jurkat Clone E6-1 cells (p ≤ 0.001) and 16.37 ± 1.10 % for K-562 cells. A majority of the cells were inhibited by the extract via apoptosis. Only U-937 cells (6.87 ± 0.65 %) showed significant necrosis compared to negative control (p ≤ 0.05). Conclusion: K-562 cells are the most resistant against garlic extract, in contrast to Jurkat Clone E6-1 cells. Garlic extract does not induce necrosis in Jurkat Clone E6-1 and K-562 cells.