Water uptake (g/100g) | 171.3 | 181.3 | 189.0
Gruel loss (g/100g) | 7.37 | 8.33 | 8.03
Hardness (N) | 15.1 | 2.1 | 17.7
Overall acceptability | 11.0 | 9.20 | 9.80
Source: Yadav et al., (2014)
Kaushal and Sharma (2014) evaluated the noodle properties made from a blend of cooked taro, rice and pigeon pea flours. The noodles were produced by blending varying proportions (20, 30, 40, 50 and 60 % levels) of taro flour with remaining equal proportions of rice and pigeon pea flours. The noodles were evaluated for anti-nutritional, cooking, textural and sensory properties. Anti-nutritional evaluation of noodles revealed decrease in phytic acid content, as the percentage of taro flour in the noodles increased. Taro flour addition produced noodles with decreased gumminess, adhesiveness, b* value and increased a* value as compared to the control sample (100 % wheat flour). Texture and color can be adopted as distinguishing parameters for analyzing the noodle samples using a principal component analysis loading plot. Noodles containing 50 % taro flour, with remaining equal proportions of rice and pigeon pea flours, resulted in the highest scores for color, taste, firmness and overall acceptability.
9.3.7 Taro-based Baby Food
Several works reported the use of taro flour for infant food formulas. Payne et al. (1941) reported that wheat and most common carbohydrate foods produce allergic symptoms, while recipes based on taro provoke no allergy and fit the restrictions of allergic patient’s diets. In addition, taro flour is readily digestible based on the small sizes of its granules. In this same vein, taro-based foods have been recently reported to be useful for persons allergic to cereals and can be consumed by infants and children who are sensitive to milk (Kaushal et al., 2015). Studies conducted in Asia in the past have also reported that babies who were fed poi, a type of baby food prepared from taro, were found to suffer less from health conditions such as diarrhea, pneumonia, enteritis and beriberi than babies fed with rice and bread (Miller, 1971). Recently, Darkwa and Darkwa (2013) highlighted the nutritive value of poi as being hypoallergenic, rich in calcium, potassium, phosphorus, magnesium, B vitamins, vitamins A and C, high in fiber and serves as a slow release energy food source. In the recent past, taro products were contemplated in commercial scales in different forms, including chips, bread, burgers and also baby food.
Ikpeme-Emmanuel et al. (2009) studied the chemical and sensory properties of three weaning food formulation made from precooked taro corms and soy flours (Figure 9.3.1). The food differed by the relative percentage of taro and soy flours in the mixture. The mix, having proportions of sucrose 13 % and vitamin mix 0.8 %, were added to each formula, while the levels of taro for the 3 formulas were 46.2, 50.2 and 60 %. The weaning food formula contained appreciable amounts of oxalate (2.99-3.38 mg/100 g) and phytate (0.07-0.58 mg/100 g), essentially originating from taro and soy flour respectively. All the weaning formula were rated to be of extremely superior quality, but less than the commercial formula used as a reference in the study. No significant difference was observed between the reference and the weaning food prepared using 50.2 % taro and 36 % soy bean. The most accepted attributes were mouth feel and consistency.
Figure 9.3.1 General flow sheet for formulation and preparation of weaning foods from taro and soy blend.
Ali et al. (2013) evaluated some properties of weaning food formula made from wheat and taro blend. Three weaning foods containing 15, 30 and 50 % taro flour were formulated. All the recipes contained 40 % chickpea flour, 4 % casein and 6 % whey protein concentrate. Wheat flour was added to the blend respectively at 35, 15 and 0 %. The substitution of wheat flour with taro flour slightly decreased protein, fat and phosphorus contents, while increasing the calcium, potassium and fiber content of weaning food formula. The amino acid content of the formula, especially aspartic and tyrosine, increased with increasing levels of taro, while others such as glutamic and proline diminished. Substitution of wheat flour with taro flour had induced an increase in oxalic acid content and water holding capacity, while the phytic acid content decreased.
Darkwa and Darkwa (2013) formulated and evaluated the characteristics of recipes for preparation of baby food in Ghana. The 4 formulas consisted of 300 g taro flour and 100 g of roasted corn flour (100 g), 300 g taro flour and 100 g of rice flour, 300 g taro flour and 100 g of soy bean flour, 100 g taro flour and 100 g of each roasted corn flour, rice flour and soy flour. For the preparation of baby food, 50 g flour mixture were mixed with 4 tablespoons of sugar, a pinch of salt and 3 cups of water, and boiled for 8 min. The sensory evaluation revealed that the taro-soy flour blend was the most accepted by the male panel, followed by the taro-roasted corn flour. In particular, the flavor of taro-soy flour blend was highly accepted. For female panelists, no significant difference was observed in the general acceptability of the baby food.
9.3.8 Preparation of Spherical Aggregate from Taro Starch
Starch aggregates are suitable agents of encapsulation for food and drugs. In the procedure of encapsulation, the granular starch is dissolved in a water solution containing the ingredient to be encapsulated. The gel produced is rapidly cooled, the water is then evaporated and a dried powder is obtained by grinding. Beside the encapsulating ability, the encapsulated molecule should be kept for a long period and released in specific conditions. As for starch, it has been shown that the release of the ingredient depends on intrinsic properties of the starch. In this respect, Forssell et al. (2004) showed that amylose content and granule size influence the rate of release of the encapsulated ingredient, with starch having high amylose prolonging the release. The starch with small granule size has the ability to aggregate into porous spheres when spray dried in the presence of small amounts of bonding agents, such as proteins or water-soluble polysaccharides (Zhao and Whistler, 1994a,1994b).
Gonzalez-Soto et al. (2011) evaluated the suitability of taro starch to aggregation. Freshly extracted starch suspension was dried in a spray dryer and the powder obtained was ground to pass through a 0.297 mm sieve. The result obtained showed that starch yield of the aggregate preparation was 76 % (tested as total starch content). The higher level of aggregate was attributed to the higher protein content 4.5 %, as compared to 2.6 % reported for amaranth starch with a low aggregate yield. According to Gonzalez-Soto et al. (2011), the high level of protein in the aggregate indicated that the procedure used at pilot plant-scale, leaves a product containing other non-starch components such as mucilage. The starch extraction included mashing of fresh taro tubers, solubilization and washing through screens number 50 (0.297 mm), 100 (0.149 mm) and 325 (0.044 mm) US mesh, until the washing water was clean. Indeed, the method of starch production used by Gonzalo-Soto et al. (2011) does not eliminate mucilage, which has been shown to exhibit binding and viscoelastic properties. Njintang et al. (2014) recently reported the yield of extraction of mucilage in various varieties of taro ranging from 30-190 g/kg corm (Table 9.3.2). This range value is similar to that reported earlier on other varieties in the Pacific (Jiang and Ramsden, 1999). In addition, the mucilage has been shown to contain 30–50 % proteins.