ECONOMIC ANALYSIS OF YAM PROCESSING INTO YAM FLOUR IN SAKI AGRO ECOLOGICAL ZONE OF OYO STATE, NIGERIA

The study examined the economic analysis of yam processing into yam flour in Saki Agro ecological Zone of Oyo State. It specifically described the profitability of yam processing; examined the technical efficiency of yam processors and determined the effect of the socio-economic characteristics on technical efficiency. Data were collected with the aid of structured questionnaire and analyzed using descriptive statistics, profitability and budgetary analysis as well as stochastic frontier model and Garrett scale. The study reveals that majority of the respondents were female (88%) with a mean age of 47. The result shows that the rate of return on investment was 12 percent. The mean technical efficiency of the processors was 85% indicating that the yam processors were relatively efficient in allocating their limited resources. Some observable variables relating to socioeconomic characteristics such as processing experience and sex of the respondents significantly explains the variation in technical efficiency. Factors such as high cost of yam tubers, poor weather condition and inadequate processing facilities are the major factors that hinder the processing activities in the study area. The study therefore recommends that government policies should be made to improve the provision of inputs such as yam tubers and capital equipment at affordable price.

The effect of lesser yam tuber flour (Dioscorea esculenta) and cooking methods on meat analogue chemical and textural properties

The addition of carbohydrates on gluten meat analogue has the potency to improve texture, such as lesser yam flour. It can be processed by steaming and baking. This study aimed to determine, analyze, evaluate the effect of cooking methods (steaming and baking) and substitution of lesser yam tuber flour (0%, 5%, 10%, 15%) on the texture of meat analogue and chemical properties only for the best meat analogue. This study used Randomized Block Design, Nested Design of 3 replications with 2 factors, levels of lesser yam tuber flour nested in cooking methods. The texture of meat analogue was compared to beef texture. The results showed that the cooking method affected hardness and cohesiveness significantly. The substitution of lesser yam tuber flour significantly affected hardness, springiness, cohesiveness and chewability. The best steamed meat analogue was at 5% substitution level of lesser yam tuber flour, contain of 49.79% moisture content, 28.39% protein, 17.04% carbohydrates, 2.57% ash, 2.21% fat and red grayish color. The best baked meat analogue was at 0% substitution level of lesser yam tuber flour, contain of 48.64% moisture content, 29.87% protein, 16.89% carbohydrates, 2.60% ash, 2.00% fat and red grayish color. The steamed meat analogue was more similar to beef, than the baked meat analogue. This production of a meat analogue would be suitable as a simple household-scale meat substituent.

Antioxidative Characteristics and Sensory Acceptability of Bread Substituted with Purple Yam (Dioscorea alata L.)

In this study, plain bread was made by substituting wheat flour with purple yam flour (Dioscorea alata, L). The addition of 0, 10, 15, 20, and 30% purple yam flour aims to increase the functional value of plain bread as a source of natural antioxidants. The bread produced with two baking temperatures (170°C and 180°C) was tested for anthocyanin levels, total phenol, antioxidant activity (DPPH free radical scavenging), volume expansion, color, and preference test. The results showed that the temperatures of the bread baking did not affect anthocyanin levels, total phenol, antioxidant activity, volume expansion, and bread color ( p > 0.05 ). The substitution of purple yam flour had a significant effect on anthocyanin levels, total phenol, antioxidant activity, volume, and bread color ( p < 0.05 ). The levels of anthocyanins, total phenol, antioxidant activity, and darker color increased with the addition of purple yam flower whereas the rate of expansion reduced. However, the addition of purple yam flour did not affect the level of preference for the bread produced. Purple yam flour can be added to the manufacture of bread made from wheat flour as much as 30% with a baking temperature of 180°C. The resulting bread contained total anthocyanins 54.62 mg/100 g db, total phenol 391.14 mg EAG/100 g db, antioxidant activity 48.53% and volume expansion 64.85%, color L ∗ = 53.06 , a ∗ = 6.52 , b ∗ = 13.32 , C = 14.87 , H = 64.06 , and sensory score = 3.24 (preferred).

Pengaruh Substitusi Tepung Ubi Gembili (Dioscorea Esculenta) terhadap Mutu dan Sifat Hedonik Brownies Panggang

Lesser-yam baked brownies is brownies made of Lesser-yam flour combined with wheat flour using different ratio as the main ingredients. This research aims to investigate the best formula and the hedonic qualities (taste, texture, and color) and the level of preferences (taste, texture, and color) of Lesser yam baked brownies. There are three different treatments of Lesser-yam flour combined i.e., 10,00 percent, 20,00 percent, and 30,00 percent. This experimental research was used Completely Randomized Design. The result data were tested statistically using ANOVA test followed by Duncan’s Multiple Range Test if showed different proceeds. The best formula to make Lesser-yam baked brownies was 10,00 percent of Lesser-yam flour that substitute wheat flour. This formula obtained the highest score of 4,49 (unbitter) in taste quality. 3,86 (rather soft) in texture quality. 3,31 (rather black-browned) in color quality. And the affordance level at taste 4,36 (favorited). 4,41 (rather like) the affordance level at texture, and 4,34 (favorited) the affordance level at color. Brownies panggang ubi gembili adalah brownies yang dibuat dengan menggunakan tepung terigu dan tepung gembili dengan perbandingan yang berbeda. Tujuan penelitian ini untuk mengetahui formula terbaik dan mengetahui mutu hedonik (rasa, tekstur dan warna), sifat hedonik (rasa, tekstur dan warna) brownies panggang ubi gembili dengan jumlah gembili 10 persen, 20 persen dan 30 persen. Metode penelitian ini adalah penelitian eksperimen menggunakan Rancangan Acak Lengkap (RAL). Data hasil analisis di uji dengan uji statistik menggunakan ANOVA dan dilanjutkan dengan uji DMRT jika terdapat perbedaan yang nyata. Hasil dari penelitian ini menunjukkan bahwa formula terbaik yang diperoleh pada brownies panggang ubi gembili dengan persentase 10 persen, nilai hasil penelitian mutu hedonik dan sifat hedonik brownies panggang ubi gembili 10 persen menunjukkan nilai mutu 4,49 (tidak langu), nilai mutu tekstur 3,86 (agak lembut), nilai mutu warna 3,31 (agak cokelat kehitaman). Sifat hedonik rasa 4,36 (suka), sifat hedonik tekstur 4,41 (suka) dan sifat hedonik warna 4,34 (suka).

Variation in the Physical and Functional Properties of Yam (Dioscorea spp.) Flour Produced by Different Processing Techniques

Research on the processing of yam (Dioscorea spp.) into flour is aimed at optimizing techniques to obtain a material with high physicochemical and functional properties. The present study investigates the effect of the processing techniques on the levels of inulin, organic acids, total phenolics (TP), antioxidant capacity, and polyphenol oxidase (PPO) and peroxidase (POD) activities, as well as on the physicochemical properties of flour derived from two yam species—Dioscorea esculenta and Dioscorea bulbifera. All tubers were peeled and sliced, then subjected to different processing techniques through blanching, soaking, and drying. The results revealed that freeze-drying appears to be the best technique in achieving the highest whiteness index of yam flour. This coincided well with the low phenolics content and POD activity, which suggests a reduced enzymatic browning reaction in the freeze-dried yam flour. On the other hand, chemical analyses showed that D. esculenta and D. bulbifera flours have the highest levels of inulin (23.0 and 27.8 g/100 g DW, respectively) and succinic acid (7.96 and 7.65 g/100 g DW, respectively) in the samples subjected to direct oven-drying. Oven drying without pretreatment neither blanching nor water steeping maintained antioxidant activity in the flour derived from both D. esculenta and D. bulbifera.