Sweet Potato Ketchup: Feasibility, Acceptability, and Production costs in Kenya.

Ketchup sauce is increasingly a popular condiment used as a flavouring ingredient in fast-food businesses in East African urban areas. It is one of a myriad of products that can be made using sweet potato (Ipomoea batatas) roots. We assessed the feasibility, consumer acceptability, and cost of production for a ketchup sauce made by substituting tomatoes with sweet potatoes. The final product, in which up to 80% tomatoes were substituted with sweet potato, was found to be organoleptically acceptable in Nairobi, Kenya. The yellow flesh colour of the sweet potato had a good influence on the final consumer preference of the product. Adding sweet potato to the ketchup formulation had little influence on the final pH, which ranged from 3.8 to 4.1. Titratable acidity values ranged from 0.36 to 0.60 g (acetic acid) per 100 g sauce. Shelf life test indicated that ketchup sauce incorporating sweet potato could safely be stored for 2 to 3 months. The addition of sweet potato in the ketchup formulation significantly reduced the production cost of the sauce. The Journal of Food Technology in Africa Volume 5 Number 1 (January- March 2000), pp. 14-1

Sweet Potato Ketchup: Feasibility, Acceptability, And Production Costs In Kenya

Ketchup sauce is increasingly a popular condiment used as a flavouring ingredient in fast-food businesses in East African urban areas. It is one of a myriad of products that can be made using sweet potato (Ipomoea batatas) roots. We assessed the feasibility, consumer acceptability, and cost of production for a ketchup sauce made by substituting tomatoes with sweet potatoes. The final product, in which up to 80% tomatoes were substituted with sweet potato, was found to be organoleptically acceptable in Nairobi. The yellow flesh colour of the sweet potato had a good influence on the final consumer preference of the product. Adding sweet potato to the ketchup formulation had little influence on the final pH, which ranged from 3.8 to 4.1. Titratable acidity values ranged from 0.36 to 0.60 g (acetic acid) per 100 g sauce. Shelf life test indicated that a ketchup sauce incorporating sweet potato could safely be stored for 2 to 3 months. The addition of sweet potato in the ketchup formulation significantly reduced the production cost of the sauce.En Afrique de l' Est, la sauce "ketchup" devient de plus en plus un condiment populaire pour aromatiser les frites dans les commerces urbains d'aliment pr\ueat-\ue0-emporter; en plus, elle est parmi plusieurs produits dont on peut fabriquer \ue0 partir de la patate douce. Dans cet article, nous avons \ue9valu\ue9 la faisabilit\ue9, l'acceptabilit\ue9 par les consommateurs et le co\ufbt de production de cette sauce, fabriqu\ue9e en substituant de la mati\ue8re premi\ue8re habituelle, de la tomate, par de la patate douce. La sauce dont le remplacement de la tomate par de la patate douce est all\ue9 jusqu'\ue0 80%, a \ue9t\ue9 trouv\ue9 acceptable sur le plan sensoriel. L'utilisation de la patate douce \ue0 chaire jaune a eu un effet b\ue9n\ue9fique sur la pr\ue9f\ue9rence du produit par les consommateurs. L'addition de la patate douce dans la formulation de cette sauce a eu peu d'influence sur le pH final du produit, et ce dernier a oscill\ue9 entre 3,8 et 4,1. L'acidit\ue9 titrable a vari\ue9 entre 0,36 et 0,60 d'acide ac\ue9tique par 100 g de sauce. Le test de dur\ue9e de vie du produit a montr\ue9 que le produit fini pouvait \ueatre entrepos\ue9 pendant 2 \ue0 3 mois sans d\ue9t\ue9rioration ou danger pour les consommateurs. L'addition de la patate douce a r\ue9duit sensiblement le co\ufbt de production de la sauce

Sweet potato ketchup: Feasibility, acceptability, and production costs in Kenya

(African Crop Science Journal 1999 7(1): 81-90

Effect of packaging materials on weight loss and nutrient quality changes of rechanded sweet potatoes (Ipomoea batatas Poir) during short-term storage

The effects of packaging materials on weight loss and nutrient quality changes of recharged submerged in clean tap water) sweet potatoes (Ipomoea batatas Poir) roots during storage were determined. Sweet potatoes from two genotypes, ‘KEMB 10\' and ‘Yanshu\' were recharged for 14 hours and packaged in perforated polyethylene bags (0.02 mm), Kraft paper bags (0.025 mm) and nylon gunnysacks, with roots placed on open plate as control. The packages were then stored at prevailing ambient conditions (23 &#177 2 oC, 77.5 &#177 5.5 % relative humidity (RH)) for 21 days. During storage the sweet potatoes\' change in weight was determined every 3 days. Change in reduced ascorbic acid, &#223-carotene, total sugars and total soluble solids contents were determined every 7 days. There was a significant (p &#8804 0.05) weight loss as well as reduced ascorbic acid loss, but total sugars and &#223-carotene contents increased during storage. Although total sugars showed an apparent gradual increase in all packages and genotypes during storage, the increase was not significant (p &#8804 0.05). Perforated polyethylene bags significantly (p &#8804 0.05) prevented weight loss (up to 1.8 %) as well as allowed for the most retention in reduced ascorbic acid (13.45 g/100 g fresh weight), and increase in &#223-carotene (4.9 mg/100 g fresh weight) and total sugar (6.4 g/100 g dry weight) contents than Kraft paper bags and nylon gunnysacks. Roots packaged in Kraft paper bags were not different in weight and nutrient quality changes from those packaged in nylon gunnysacks. The control sweet potatoes always showed the highest losses in weight (up to 27.8 %) and nutrient quality. Packaging materials did not affect total soluble solids content during storage. The results show that packaging in perforated polyethylene bags can improve shelf life of recharged sweet potatoes by 14 days.Keywords: Ipomoea batatas; packaging; weight lossJAGST Vol 6(1) 2004: 29-4

Évaluation post récolte de six génotypes de patate douce sélectionnés a l'est du Congo

Six variétés de patate douce étaient évaluées en deux répétitions dans le temps (1998 et 1999), pour leurs potentiels post - récoltes comprenant les qualités organoleptiques, nutritionnelles et conservatoires. Aprés l'appréciation de la forme et la couleur de la peau des tubercules frais, les tubercules bouillis ont subit l'évaluation de la texture, la saveur, la couleur de la chair et l'acceptabilité globale par un panel de 30 dégustateurs non formés. Un autre lot de tubercules frais de mêmes variétés fut mis en conservation pendant 60 jours dans trois modes paysans de conservation (grenier, panier et fosse) pour évaluer les pertes dues à l'évapotranspiration, aux pourritures, à la germination ainsi que l'évolution au cours de temps de stockage de la teneur en protéines, en vitamine A et en matière sèche. Les résultats obtenus ont montré que les variétés Benikomachi et Caroline. Lee très appréciées pour les qualités organoleptiques se sont caractérisées par un taux de matière sèche élevé (41% et 39%), une forte détérioration d'aspect extérieur après conservation et, les pertes de poids les plus élevées soit 37%. Les variétés Yanshu 1 et White Delite moins appréciées pour les qualités organoleptiques, affichent un taux de matière sèche faible (26% et 28%) et une perte de poids après conservation s'élevant à 31%. Les variétés Mugande et Karebe II de qualités organoleptiques intermédiaires présentent un taux de matière sèche intermédiaire 36% et 38%, avec les pertes de poids les plus faibles (27%). Quant à la vitamine A et aux protéines, elles ont subit une perte de 20% au bout de 60 jours de conservation. Cependant cette diminution de potentiel nutritionnel n'était pas lié au mode de conservation. Le mode de conservation en fosse est celui qui a occasionné la plus faible perte de poids (21,9%) mais avec un taux de germination le plus élevé (cote 4). Cette étude qui était une évaluation de germoplasme en qualités organoleptiques et en potentiel de conservation a permis d'identifier les variétés Mugande et Karebe II comme étant les meilleures. Mots Clés: Conservation, fosse, grenier, panier, patate douce, vitamine A (African Crop Science Journal 2001 9(1): 33-41

Influence of age, farming site, and boiling on pro-vitamin A content in sweet potato (Ipomea batatas (L.) Lam.) storage roots

To maximize the availability of pro-vitamin A carotenoids in sweet potato and to recommend the appropriate start of piecemeal harvesting practice, the main carotenoids in storage roots of 17 different sweet potato cultivars were surveyed using HPLC and spectrophotometry methods, and their variation due to production site, storage root age, and boiling was assessed. There was significant variation in carotenoid content among cultivars. Six different carotenoids were consistently detected in significant quantities. Orange-fleshed roots contained higher total carotenoid and Beta-cartotene content than white- and cream-fleshed lines, and all trans-Beta-carotene predominanted. The effect of storage root age on carotenoid content was significant. Twelve weeks after planting, the yield and amount of pro-vitamin A present in roots of orange-fleshed cultivars evaluated were high enough to provide adequate dietary pro-vitamin A and suggest the start of piecemeal harvesting. The effect of farming site on total carotenoids was significant; however, the amount of Beta-carotene was not different over three testing sites. Boiling of roots for 30 min caused a reduction in total carotenoids which varied by cultivar, however, further boiling for up to 60 min did not exacerbate the reduction in total carotenoids