Food Products
Rootcrops such as cassava, sweetpotato, yam and taro are energy foods with low glycemic index and high dietary fibers. They also contain vitamins, minerals and micronutrients. Purple yam, sweetpotato and taro contain anthocyanin which is an antioxidant. A number of food products have been developed at the Philippine Root Crop Research and Training Center, Visayas State University, Baybay, Leyte such as fermented and non-fermented foods. Fermented foods include the dessert wines, Sweetpotato pickles and yogurts and non-fermented foods are the vacuum-fried (cassava, sweetpotato, taro and cocoyam), extruded (puffed and chippy from cassava), bakery (cookies, bread, muffins, macaroons and brownies) and other local food delicacies (pitsi-pitsi and espasol).
Taro Wine
Taro wine was produced using the starter from China, Cambodia Kampong Cham, Takeo Province, Vietnam and all kinds of microorganisms (molds, yeasts, bacteria, LAB) were isolated. Taro wine fermentation using 50% glutinous rice and Taro VG-9 (flesh with peel, peel only and flesh only) as substrates was conducted in order to understand the effect of peel in the physicochemical characteristics of wine and antioxidant activity. Results showed that TSS, pH and TTA has significant effect on peel while there is no significant difference in yield and antioxidant activity of wine. Taro wince with taro peel only had the lowest TSS among the samples. This may be due to the less starch content of taro peel that the microorganisms resulted to convert less sugars. Meanwhile, pH of taro wine with flesh only (pH 4.06) was found to be the highest among samples and Taro wine with the flesh and peel had the highest TTA with 1.11%. On the other hand, Taro wine using taro flesh with peel had the highest antioxidant activity followed by with peel only and flesh only. This may be implied that peel contributed to the increase of the antioxidant activity of wine due to the presence of the anthocyanin, the purple color of the peel but there was no significant increase among the wine tested.
Cocoyam Yogurt
A secondary shelf life study of flavored yogurt was conducted to verify the results of the first experiment. Microbial count and pH values were within the set standard, which is ≥ 106 for a minimum lab count and pH not higher than 4.5 for fermented milk products. In this regard, mango and pineapple flavored cocoyam yogurt can be stored at 3°C for as long as 7 weeks, a week longer than the first experiment. In the case macapuno-nata, maximum storage of 4-5 weeks is the best as further storage exhibit a strong “lana” aroma, validating the first experiment’s results.
Additives such as flavoring tend to reduce the consistency of the product. Therefore, the yogurt generally needs some stabilization. In the attempt to improve the consistency and texture of cocoyam yogurt, level of cocoyam puree was increased but showed no improvement in the texture and consistency. Other possible stabilizers were explored; gelatin and commercial yogurt stabilizer. No improvement in consistency and texture was observed based on the acceptability scores with the use of either stabilizer. The addition of commercial stabilizer significantly lowers the LAB count of the yogurt.
Dessert wine
Dessert wines were produced from 100% rootcrop and 50:50 combinations with either black glutinous rice or white glutinous rice using local bubod from Baguio as a starter. Rootcrops used include sweetpotato (sp-25, wonder), Cassava (Lakan 1, Lakan 2, Rayong 5), Taro (VG-9, VG-1), and Yam (VU-2, VU-5) with and without glutinous rice. The total volume of wine produced from rootcrops with 50:50 ration of rootcrop and glutinous rice had significantly higher TSS values and percent alcohol content those without glutinous rice. The pH value of wines ranges from 3.62-4.43 and TTA ranges from 0.37-1.51. Anti-oxidant activity of wine from most rootcrops with black glutinous rice is relatively higher than those with rootcrops only. However, wine from 100% light-colored rootcrops was observed to have higher anti-oxidant activity compared to light-colored rootcrops with white glutinous rice. Due to small amount of yield, 100% rootcrop wines were not subjected to sensory evaluation. From 50:50 set-ups from light-colored rootcrops with white glutinous rice, ca ssava (rayon 5) has the highest general acceptability while taro (VG-1) was significantly least acceptable in all sensory parameters.
Ready-to-Eat high Energy Bars
To produce such a bar, flours from major root crops were screened based on its energy content, functional and physico-chemical property, and sensory acceptability. Flours used were from cassava (Rayong 5 and Lakan 1), sweet potato (Minamon and Tabangas), taro (BLSM 151 and BLSM 116), and apali (VT-5).Based on the results of the screening and sensory evaluation, it is clearly justified that cassava based bars had better qualities compared to sweet potato, taro, and apali based bars. Screening of other energy sources revealed that use of margarine as fat source and binding agent was most preferred.
Choco-cookies
The voluminous solid mass waste from dessert wine production (50:50, taro:rice) was utilized into food by addition to choco-cookies using either cassava flour or grates as base component. An optimized region for production of biomass choco-cookies was determined and verified by comparing cookies made within and outside the optimum region. Another verification test was conducted to compare cookies made within the optimum region. Sensory acceptability scores showed that no significant difference was found between the cookies and scores were not lower than the set limit of 6.7.
Food products from grates
There are four newly developed food products from dried cassava grates namely; Yuca Puffs, Cacharon, Extruded noodles and grains. Out of all these food products, yucca puffs have the highest potential for commercialization to its simple processing operations, sensory qualities and market acceptability. These newly developed extruded food products from cassava were pilot – tested, and have enhanced nutritional value and at least 1 year shelf life.