Development of lactose free dairy dessert


Thesis Type: Postgraduate

Institution Of The Thesis: Orta Doğu Teknik Üniversitesi, Faculty of Engineering, Department of Food Engineering, Turkey

Approval Date: 2015

Student: SULTAN GARAYEV

Co-Supervisor: SERPİL ŞAHİN, HALUK HAMAMCI

Abstract:

A recent trend in food industry is to develop lactose free food products due to the large number of consumers suffering from lactose intolerance. In this study, lactose free desserts were developed by using two different starches; waxy maize and amylomaize. Concentrations of waxy maize and amylomaize were 0.032, 0.040, 0.048 g/ml and 0.064, 0.072, 0.080 g/ml, respectively. Lower concentration of waxy maize starch was enough for body formation and gel like structure, implying waxy maize was more effective in dessert production. Also the effects of gum type and concentration on the physical properties of lactose free desserts were investigated. Guar, arabic and κ-carrageenan gums were used at two different concentrations (1% and 0.5%) in the formulations. Among them κ-carrageenan was the most effective one, leading by guar and arabic gum. Increasing gum concentrations led to improvement in the textural properties of dairy desserts. Effect of sucrose concentrations (0.10 g/ml and 0.14 g/ml) on waxy maize and amylomaize was different. Addition of sucrose caused decrease in textural properties of waxy maize starch containing desserts, on the other hand sucrose addition increased textural properties of amylomaize containing desserts. In addition, lactose free dessert formulation containing the same concentration of sucrose with lactose containing desserts was less liked by the panelists. Therefore, it is required to reduce the amount of sucrose in lactose free dessert production. Lactose free dessert with reduced sucrose was the most acceptable formulation in terms of texture also. Color of different dessert formulations was similar. NMR spin-spin relaxation times were obtained for desserts with different formulations in order to better understand molecular level of gelatinization and results showed that starch and gums compete for water in the medium. Comparison of lactose containing and lactose free desserts was carried out too. Results show that texture of desserts were similar when waxy maize starch was used with 0.14 g/ml sucrose concentration. However, when amylomaize was used lactose containing desserts had lower textural properties than those of lactose free desserts.