In this article I will be writing on two methods of preserving and improving the quality of locust beans namely: salting and drying. 80g of non-salted sample of locust beans and the same quantity of the sample with 5g of salt and 10g salt were subjected to direct sunlight drying for 5days. Proximate analysis showed that dried salted sample contains 67.65% of protein while dried non-salted sample has 66.82% of protein. The non-salted sample has a microbial load of 1.02×107cfu/g while the salted sample has 1.42×105cfu/g at the end of the fifth day of drying. The non-salted has the greatest drying rate while the 10g salted sample has the least drying rate.
Locust Bean (Parkia biglobosa) belongs to the leguminous group used in many food dishes `in West Africa. It was gotten from the Locust bean tree that grows in the savannah area of West Africa. The tree has feathery doubly divided leaves, red flower and long narrow pods and it has black seed. It contains about 38% protein, 31% fat and, 23.6% carbohydrate when it is moisture free and 30% protein, 15% fat, 49% carbohydrate when fermented [1]. It is known as ‘Iru’ in Yoruba language,south western Nigeria ‘Kipaluga’ among the ‘Kusasis’ and‘Dagommbas’ of Northern Ghana, ‘Kinda’ in Sieria Leone and ‘Netetu’ or ‘Soumbia’ in Gambia and Burkina Faso [2]. Locust beans are medicinal and used as mouthwash to relieve toothaches. The beans husk (seed coats) is used with indigo dye to improve the luster of fabric while the tree bark yields red tannin for dying leather. It is normally used as a soup or stews flavouring materials and constitutes an essential ingredient in preparation of local soup or stew [3]. Preparation of Locust bean starts with boiling for 12 hours and further soaking in boiling water for another 12 hours, preferably overnight. Excess water was drained off and the seeds were dehulled by marching the seeds with the feet in a large wooden mortal. Further removal of the seed coat was achieved by rubbing the cotyledons between the palms of the hand and thereafter washed with water. The cotyledon was again cooked for another 6 hours, the hot boil water was drained off and the cotyledon were then spread into calabash trays, covered with wooden trays, wrapped with jute bags and fermented for 3-4 days to produce iru [4]. The long boiling period can however be reduced by using a pressure cooker to boil the locust bean. A softening agent called ‘kuru’ containing sunflower seed and ‘kuru’ may be added during the second boiling to aid softening of the cotyledons. After boiling, the seeds were drained and spread in calabash trays in layer of about 4cm depth. About two or three trays are stacked together and wrapped in many layer in jute sacks and coarse cotton cloth to provide warmth and a humid atmosphere. The seeds ferment for about 36hours [5]. It was reported that Locust bean fermentation is solid substrate fermentation; this is unlike most other fermentation of food in West Africa, which is usually in liquid menstrum, the temperature of 25OC-30OC to 45OC-50OC [6]. The fermentation temperature is 37.5oC after 24hours and 39oC after 36hours, when a starter was used. During the three days of fermentation, the cotyledons change in colour from light brown to dark brown and become softer [1,7].The results of the chemical analyses indicate that fermentation resulted in protein enrichment of the fermented locust bean. Fermentation also imparts a characteristic flavour and odour to the beans [8].Fermented beans have a greyish sticky mucilage covering and a strong ammoniac smell. This peculiar odour and flavour enhance its taste in traditional soup used to eat root and tuber diets. Salt is added to preserve the bean [9]. The locust bean also known as carob has several uses in food and medicine. It is rich in insoluble fibre.
In conclusion,it is clear that salting and drying improved the quality of locust bean.Since the harvest of locust bean is seasonal, the need for preservation cannot be over emphasized,this work has presented the optimum conditions for locust bean preservation. (1) 5g of salt is enough to preserve and maintain 80g of locust bean nutritionally.(2) 3 days of drying is adequate to fully preserve 80g of locust bean.(3) Non-salted locust bean has more microbial load than salted locust bean.(4) Non-salted sample dry faster than salted sample.(5)Salted sample is more nutritional than non-salted sample
