Saqib Arif

Effect of pentosans addition on pasting properties of flours of eight hard white spring wheat cultivars.

The effects of water extractable pentosans (WEP) and water unextractable pentosans (WUP) on pasting properties in flours of eight different hard white spring wheat (HWSW) cultivars was studied. WEP and WUP isolated from a hard wheat flour were added to each of the cultivars at 1% and 2% level. The results indicated that WEP exhibited a pronounced effect on pasting properties as compared to WUP and variety. Univariate analysis of variance (ANOVA) was used to evaluate sources of variation. The variety significantly (P < 0.001) influenced all the pasting parameters. WUP caused significant (P < 0.001) variation in paste viscosities (except breakdown). WEP influenced more pronouncedly the hot paste, cold paste, breakdown and setback viscosities with F values—221.802, 214.286, 98.073 and 120.159, respectively. Variety-by-WEP interaction exhibited significant (P < 0.01) influence on pasting time, peak, hot paste and cold paste viscosities. Whereas, variety-by-WUP interaction only significantly (P < 0.001) influenced the pasting- time and -temperature. Duncan’s test was used to analyze the significant difference (P < 0.05) within the variety. The results revealed that WUP did not induce significant (P < 0.05) influence on all the pasting parameters, whereas, WEP influenced significantly (P < 0.05) the paste viscosities of some of the varieties. It was also found that the addition of WEP remarkably reduced the setback, hot paste, cold paste viscosities and increased the breakdown viscosity in all cultivar flours. The effect of WEP was greater at higher level of supplementation on paste viscosities.

The Impact of Sun Drying on the Occurrence of Aflatoxin in Red Chilies

Abstract: A major challenge in post-harvest protection of chilies is its rapid drying to prevent quality deterioration as a result of fungal contamination. The speed and efficiency of drying is crucial as the improper and prolonged drying may eventually initiate the buildup of mycotoxins. This research demonstrated levels of aflatoxin in samples at different stages of drying with the objective to assess the efficiency of the common practice of on-farm sun drying in Pakistan. The results indicated that there was no significant pre-harvest contamination of aflatoxins in chilies grown at different locations under study. Sun drying of the harvested chilies over a post drying stage reduced average moisture content from 69.70% to 9.87%, but also led to a gradual increase in the level of aflatoxins. The correlation between the observed increase in aflatoxin levels and the length of the drying period was found to be statistically significant (P<0.05) at all the locations investigated. The implications of the findings are discussed in relation to optimizing the post-harvest drying process to minimize the levels of aflatoxin in chilies.