Tofu Processing at Tofu Industry Using Fermented Whey as Coagulants

Background: Tofu industry in Indonesia commonly used fermented whey as coagulant. There is a lack of study about tofu producing process which used fermented whey. Generally, the society determine the tofu quality from the texture, however, the industry itself tend to produced tofu rendement. In the tofu industry, the yield and texture of tofu is a very important process parameter. The yield and texture are influenced by various factors, such as the soybean extraction process, cooking temperature, coagulation pH, length of coagulant addition, intensity of coagulant addition, or duration of shaping and pressing. However, every tofu factory applies different levels for each factor. This condition causes the variation in the characteristics of tofu, especially with regard to its texture and yield. Objective: This study aimed to determine the factors that affect the quality and quantity of tofu. Methods: The survey study was conducted among the 21 tofu factories using fermented whey as the coagulant. Results: Based on the survey results, there were seven variables that determine the yield of tofu; the soybean type, soybean and water ratio, pH of fermented whey (coagulant), coagulation temperature (°C), coagulation pH, intensity of coagulant addition (time), and duration of molding (minutes). Conclusion: The six factors that influenced the tofu texture were soybean type, soybean and water ratio, coagulation temperature (°C), coagulation pH, coagulation time (minutes), and duration of molding (minutes).

ANALISA PENGENDALIAN KUALITAS PRODUK TAHU DALAM PERSPEKTIF EKONOMI ISLAM

This article is based on a fact that many food that is mixed by dangerous chemistry substances for healthy. Based on this, the writer wants to know whether the quality control process of tofu can be done without dangerous chemistry substances. Furthermore, the writer also wants to know the quality control process based on Islamic economy concept. Based on the research, it can be concluded that the key of tofu quality control lies on four things namely: raw material quality, water quality, avoidance the use of dangerous chemistry substances, and human resources quality. The tofu quality control is appropriate with the Islamic economy concept because it helps to avoid social obligation namely producing qualified human primary needs. Producing tofu is not for getting benefits only, since it is important product needed by community, and the important control is keeping the tofu quality for producing halal product. Keywords; quality control, tofu product, product quality, Islamic economy

Influence of globulin subunit composition of soybean proteins on silken tofu quality. 2. Absence of 11SA4 improves the effect of protein content on tofu hardness

Soybean variety Bunya was developed in Australia to provide a better quality bean for tofu manufacturers. It is null for globulin subunit 11SA4. We investigated the effect of both the Bunya genetic background and the11SA4 subunit on tofu properties using genotypes containing 11SA4, with and without Bunya parentage, or lacking 11SA4 with Bunya parentage. Both Bunya parentage and 11SA4 significantly influenced globulin subunit composition and tofu texture. The group lacking 11SA4 had lower seed protein content, the largest seeds and the highest 7S and the lowest 11S content and produced the hardest tofu. Examination of the impact of 11SA4 null on tofu texture at four protein contents (380–440 g kg–1) over four coagulant (2.0–3.5 g kg–1) levels revealed that the absence of 11SA4 produced firmer tofu across the protein and coagulation levels tested, and this difference was larger than that from higher protein or coagulation levels. These results demonstrated that the absence of the 11SA4 subunit could increase tofu hardness to a level that otherwise could only be achieved with much higher seed protein content.

Influence of globulin subunit composition of soybean proteins on silken tofu quality. 1. Effect of growing location and 11SA4 and 7Sα’ deficiency

Growing location and genotypes are known to affect the subunit composition of the major storage proteins of soybeans, β-conglycinin (7S globulins) and glycinin (11S globulins), which have been associated with tofu quality. In this study, we examined 16 soybean genotypes grown at two locations in Queensland, Australia, for the influence of globulin subunit composition, growing location and genotype × growing location interaction on seed, soymilk and silken tofu properties. These genotypes comprised four groups: with all globulin subunits, without 11SA4, without 7Sα’, or without 11SA4 and 7Sα’. There were significant differences in the major protein subunits among the genotypes and the four groups and between locations. Significant genotypic and location differences were also observed in the properties of the seed, soymilk and silken tofu. There were no significant genotype × location interactions. The group without 11SA4 had less 11S and more 7S globulins, resulting in the lowest 11S/7S ratio. The silken tofu from this group had firmer texture and less water loss than the group containing all globulin subunits. The results suggested that genotypes of differing globulin subunit composition may produce tofu with different qualities and the effect of globulin subunit composition on tofu quality could be affected by growing location and the absence of certain globulin subunits.

Development of a Novel Fiber Optic Sensor for On-Line Monitoring of Soymilk Coagulation

Mechanical evolution of soymilk coagulation was investigated using a novel fiber optic sensor in order to solve the problem of instability in Chinese traditional tofu quality. The sensor signal was measured, and studied the effects of temperature, soymilk concentration, and calcium chloride solution concentrations on tofu making parameters. The scattering light ratio followed a sigmoid increase during soymilk coagulation. Tofu firmness, tofu moisture content, and tofu yield were predicted from the time to the maximum slope of the first derivative of scattering light ratio. The proposed mathematical model shows potential for on-line monitoring of soymilk coagulation.