IMPACT OF PHOSPHINE ON QUALITY PARAMETERS OF STORED PERISHABLE COMMODITIES

Abstract

Phosphine fumigation is commonly used worldwide for managing storage pests in food grains, with documented applications for pest control in export-oriented perishable commodities such as fruits, vegetables, and flowers. This study aimed to evaluate the impact of phosphine fumigation on the nutrient and physical quality parameters of key perishable commodities, while also investigating sorption and residue levels. The perishables under investigation included Mango and Pomegranate (fruits), Bitter Gourd and Green Chilli (vegetables), and Rose and Chrysanthemum (flowers). The research was conducted over two consecutive years for the perishables to assess the reliability and reproducibility of the results. The results demonstrated that phosphine fumigation did not significantly alter the key quality parameters, including firmness, moisture content, total soluble solids (TSS), ascorbic acid, total phenolic content, antioxidant capacity, and total carotenoid/anthocyanin content for all the treated commodities. These are essential indicators of both the texture and nutritional value of perishable goods. The statistical analysis showed that the p-values for all these parameters were greater than 0.05, which indicates that the differences observed in the quality attributes were not statistically significant. This suggests that, despite varying concentrations of phosphine and different exposure times, the fumigation process did not cause any measurable changes in the physical characteristics or nutritional composition of the commodities. The lack of significant effect on these quality parameters indicates that phosphine fumigation, when applied under the specific conditions (such as phosphine concentrations, exposure durations, and environmental conditions), effectively preserved the overall quality of the produce. These results are important because they suggest that phosphine fumigation can be used as a treatment method without negatively impacting the marketability or nutritional quality of the perishable commodities. Sorption analysis revealed varying results among the commodities. Mango exhibited minimal sorption of phosphine, with values consistently ranging between 10-12%. Bitter gourd displayed a more variable sorption pattern, peaking at 20% after 8 hours and decreasing to 5-7% after 15 hours. Chilli, on the other hand, showed the highest sorption levels, reaching up to 60% after 8 hours of exposure, before declining to 30- 34% after 10 hours. Chrysanthemum exhibited slightly higher sorption and residue levels compared to Rose, although the differences were not statistically significant. Chrysanthemum sorption levels varied, with a wider range of 10-15%, suggesting a higher level of fumigant uptake. Despite these differences, statistical analysis (ANOVA and regression) revealed no significant effect of exposure period on sorption levels (p > 0.05), suggesting that factors other than the exposure period, such as the viii structural characteristics, and type of commodity, may influence sorption and residue accumulation. Residue analysis using gas chromatography with an FPD detector indicated low levels of phosphine residues across all commodities. Mango residues ranged from 0.009 to 0.01 µL/L, which is well within the permissible limits (0.01 ppm) for food safety. Chilli samples exhibited negligible phosphine residues after aeration, further confirming the safety of using phosphine. Bitter gourd, while exhibiting slightly higher residues after shorter aeration times, remained within the Maximum residual limits (MRL) prescribed by regulatory bodies, supporting phosphine’s suitability for use in food exports. In conclusion, this study demonstrates that phosphine fumigation, when applied under controlled conditions, is an effective method for maintaining the quality of export oriented perishable commodities while minimising residue accumulation. The findings suggest that phosphine can serve as a safe and viable alternative to other fumigants such as methyl bromide. However, the variation in sorption patterns across commodities indicates the need for further optimisation of fumigation protocols, particularly for exposure periods and concentrations, to ensure both effective pest control and the preservation of product quality.