Comparative study of hermetic and non-hermetic storage on quality of cowpea in Ghana

Cowpea (Vigna unguiculata) serves as a major food and income generation crop for millions of people in sub-Saharan Africa and Central America. However, post-harvest losses associated with this crop still remain a critical issue of concern in most developing countries. This study was therefore carried out to investigate the effect of hermetic and non-hermetic storage on cowpea in plastic containers in the tropics. The cowpeas were stored in hermetic and non-hermetic containers over a period of 12 weeks. The parameters evaluated were the moisture content, insect infestation, usable proportion, and 1000 grain mass in both hermetic and non-hermetic systems. The moisture content in the hermetic containers increased slightly from 11.7 to 11.9% compared to a sharp increase from 11.7 to 17.2% in the non-hermetic plastic containers. From the fourth week to the twelfth week, the number of live insects drastically reduced to zero in the hermetic system. In the case of the non-hermetic containers, the population of live insects/100 g of grains increased from 5 on week 0–71 on the twelfth week. Also, the mass of 1000 grains reduced from 156.50 g on week 0–145.21 g in the non-hermetically stored grains, while the hermetically stored grains recorded a decrease to 148.95 g. Finally, the usable proportion of grains in the hermetic system declined from 98.55 to 94.80% after 12 weeks of storage as compared to the drop to 85.69% seen in the non-hermetic system. Based on our findings, it was further concluded that hermetic storage could offer a better way of storing cowpea as compared to the non-hermetic system.