The Effect of Incubation Time to The Physicochemical and Microbial Properties of Yoghurt with Local Taro (Colocasia Esculenta(L.) Schott) Starch as Stabilizer

Abstract

The effect of incubation time by using three culture starters (Lactobacillus acidophilus, Lactobacillus bulgaricus and Streptococcus thermophiles) and Taro (Colocasia Esculenta) starch as a stabilizer on the physicochemical and microbial characteristics of yoghurt were investigated. One of the problems in making yoghurt is the occurrence of syneresis caused by the unstable casein micelles. The addition of natural stabilizers is known to be able to solve the problem. In this research, local taro was added to the yoghurt as stabilizers followed by different incubation time (18-h, 24-h, 30-h, 36-h and 42-h). The results showed that incubation time had a highly significant effect (p<0.01) on viscosity, whey holding capacity (WHC), moisture content, carbohydrates, pH value, total acidity, and total lactic acid bacteria. During the fermentation process, the prolonged incubation time resulted in increased acidity, viscosity, WHC, and total lactic acid bacteria, while simultaneously decreased the pH value, moisture and carbohydrate content. The research concluded that 36 h incubation time produced the best yoghurt characteristics made with Lactobacillus acidophilus, Lactobacillus bulgaricus and Streptococcus thermophiles as culture starters and taro starch as a local Indonesia stabilizer.

Properties of Malanga Flours and their Use in Pastes and Gluten Free Breads

“…Malanga production is limited, because the losses of these crops in the field represent more than 80% due to phytosanitary problems attributed to the rotting of corms and cormels during storage (Medero et al, 2016). These values double what the FAO (2019) estimates to be acceptable annual losses in the case of global food crops. Because of that, initiatives like the production of flours or starch could enhance applications extending the shelf-life of those crops.…”

“…-Chapter 2. Calle, J., Benavent-Gil, Y., Garzón, R., & Rosell, C. M. (2019). Exploring the functionality of starches from corms and cormels of Xanthosoma sagittifolium.…”

“…The protein content constitutes about ~11% on dry matter basis , while fiber is present at levels of ~19.74 % of total dry weight. According to Wada et al (2019) protein content differs depending on the type of malanga. Indeed, they reported the crude protein content of green (8.48%) and purple (10.10%) Xanthosoma spp., concluding that protein content in Xanthosoma spp.…”

“…Similarly, the reduction of other antinutrients like phytates and tannins have been investigated. Wada et al (2019) evaluated the antinutrient content of different varieties of Xanthosoma spp., showing that the content of phytates (187.57 mg 100 g -1 ) and tannins (156.11 mg 100 g -1 ) in purple Xanthosoma spp. were significantly higher than those (phytate 167.76 mg 100 g -1 and tannin 139.62 mg 100 g -1 ) in green Xanthosoma spp.…”

“…Kaur et al (2013) attributed these high values to the presence of high amount of carbohydrates and mucilage or gum . Coronell-Tovar et al (2019) explained that WAC was associated with the rise of the amylose leaching and changes in starch microstructure (loss of crystalline structure). For all these reasons, Kaushal et al (2012) suggested the use of Colocasia spp.…”