EFFECT OF NaCl AND WATER CONTENT ON EXPANSION AND COLOR OF CASSAVA AND POTATO STARCHES ON BAKING

Abstract

ABSTRACT Due to the importance of the role of NaCl in starch‐based systems, the effect of NaCl and water content on specific volume, color parameters and moisture loss of cassava and potato starches was studied and response surface methodology was used to find and estimate any nonlinearity between the parameters under study. Glass transition (Tg) is one of the main factors determining the quality parameters of toasted and baked samples. Therefore, Tg of two starch systems (cassava and potato) at low water levels (<20%) as affected by NaCl and water content was investigated. Using experimental modeling, equations were obtained to relate expansion, color change and moisture loss of baked samples to salt level and water content. Differential scanning calorimetry‐measured Tg showed that NaCl had negative impact on glass/rubber transition temperature of starch–salt mixtures compared with the samples without NaCl. This could have practical implications in baking, toasting and extrusion processing of starch‐based systems.PRACTICAL APPLICATIONDue to concerns over health‐related issues of high intake of salt by the consumers, recently, the reduction of salt in different food products has become the focus of many industrial projects, conferences and workshops. In breakfast cereals, other than starch type, other added ingredients such as sugar and salt can have profound effects on the physical characteristics of final products. The inclusion of salt in breakfast cereals has some important technological roles, e.g., structure formation and flavor and color generation. Salt plays a key role in the expansion of low‐moisture extruded starch‐based products. Using the findings of this paper, one may quantify the effects of salt level on expansion and color of baked, toasted or extruded starch‐based cereal products and relate the changes to the glass rubber transition of the system.