International Journal of AgriScience Vol. 4(8):414-419, August 2014 www.inacj.com ISSN: 2228-6322© International Academic Journals International Journal of AgriScience Vol. 4(8):414-419, August 2014 414 Comparative evaluation of storage losses, nutrient and mineral composition of three edible species of cocoyams in Nsukka, Nigeria EZE C.S. 1 , Nwani C.D. 2* 1 Department of Applied Biology, Enugu State University of Science and Technology (ESUT), Enugu Email: chumaeze2010@yahoo-com 2 Department of Zoology and Environmental Biology, University of Nigeria Nsukka *Corresponding author Email address: didigwunwani@yahoo.com; chris.nwani@unn.edu.ng Received in June 2014; accepted in revised form July 2014 ABSTRACT Comparative evaluation of storage losses, nutrient and mineral composition of three edible cocoyams (Colocasia esculenta L. Schott, Colocasia antiquorum L. Schott and Xanthosoma sagittifolium L. Sohott) was carried out. Fresh weight loss, sprouting and rotting of the cocoyam corms were assessed. Nutrient and mineral composition of the three species were also assessed. Loss in fresh weight was significantly higher (p < 0.05 among C. esculenta corms followed by C. antiquorum while X. sagittifolium had the least. Sprouting was significantly low (p< 0.05) among X. sagittifolium compared to others. Rot incidence and severity were significantly higher (p < 0.05) among C. esculenta while they were significantly low (p< 0.05) among X. sagittifolium. Carbohydrate content was highest in X. sagittifolium and lowest in C. esculenta while the opposite was the case for crude protein content. There was little variation in crude fibre, crude fat, ash and moisture contents among the three species. The results showed that potassium, calcium, magnesium, sodium, phosphorus, iron, manganese, copper and zinc were present in all the cocoyam species with varying concentrations though magnesium and potassium were highest in concentration followed by calcium. Keywords: comparative evaluation, storage losses, nutrient composition, mineral composition, edible cocoyam species INTRODUCTION Food storage has played important role since the beginning of cultivation and settlement of mankind. The role of food storage is to absorb the variations in supply so that crops may be channeled to consumers as and when required and at a reasonable price. To this end, storage of cocoyam corms is often necessary in order to preserve planting materials over a seasonal period or to preserve the corms while awaiting favourable marketing conditions or to make them available for food at all times of the year. After the cocoyams are harvested, they are kept in storage for subsequent use as food as well as for planting during the next planting season. While in storage, rotting is a very serious factor limiting both the quantity and quality of the crop available for human consumption and for the next planting season. An estimated loss of 40-50% due to rotting of the corms in Nigeria during storage has been recorded (Arene, 1980, NRCRI, 1980). Several reports has shown that this rotting of corms during storage is caused primarily by microbial agents especially fungi (Eze and Maduewesi, 1990, Eze, 1991, Ugwuanyi and Obetta, 1996, Nwachukwu and Osuji, 2008, Eze and Ameh, 2011). In addition to rot, losses are encountered due to sprouting during storage. Eze and Maduewesi (1990) showed that the incidence of sprouting which just began after one month in storage progressively increased with storage period in all the storage methods they employed and all the corms sprouted before the six months in storage. Similar findings have been reported by Gollifer and Booth (1973), Numfor and hyonga, (1987). Gollifer and Booth, (1973), observed that if storage rot of cocoyams were controlled, sprouting would be an important factor in reducing the storage life and quality of the corns. Loss in fresh weight is another problem facing stored cocoyam corms. Praquin and Miche (1971) recorded a weight loss of 12-15% for sound corms after 4-6 months in storage in Cameroon. Gollifer and Booth (1973) found that just after one month of storage, the corms of C. esculenta have lost up to 35% of their initial weight. In Nigeria, Eze and Maduewesi (1990) recorded a weight loss of up to 20% for C. esculenta