تأثیر جایگزینی شکر با اریتریتول بر ویژگی‌های فیزیکی شیمیایی، بافتی و حسی بیسکویت

Introduction: Food science has meet new challenges in food production that could respond consumer’s tastes and at the same time improve. Lifestyle modifications related to change in the eating quality and quantity along with mental stress led to the prevalence of non-communicable diseases. Based on the consumer’s demand, food scientists are now focusing on developing low-calorie/high-fiber functional foods. Biscuit is one of the bakery products that is used widely through stratum. Approximately 100-gram biscuit contains 77-gram carbohydrate, 8-gram protein and 13.5-gram fat and produce 465 Kcal energy. Sugar is one the most important ingredients in biscuit formulation and possess the highest amount in formulation after flour and has a major role in creation of a desirable sweet flavor, obtaining moisture, creation of texture, reduction in retrogradation and increase in shelf life of the product. However, sugar has a lot of harmful effects such as diabetes, tooth decay, obesity and cardio vascular diseases. So decreasing sugar content in food formulation is very vital. Considering key role of sugar, a proper substitute should be selected so that quality characteristics of the product maintained. Stevia has sweetening amount about 300 times than sucrose because of its diterpenoid glycosides. Sugar alcohols or alditols such as sorbitol and erythritol are poly-ols that can be used in food formulations as low-calorie low- digestion sweeteners. Regarding use of biscuits a serving in food regime due to high nutritional value and importance of presence of different dietary biscuits relative to different tastes in food basket and the advantages of reducing sugar in food habits, so production of low calorie biscuit using sugar alditols is the main aim of current research.
Material and methods: In current research wheat flour was purchased from Behnam factory from Torbat- e Heydarieh. Erythritol were used as sugar replacer and was obtained from Iran Stevia Company, Tehran, Iran. All biscuit dough’s were produced in a way that ratios were as: four 300 gr, sugar 75 gr, confectionary oil 64.8 gr, water 34.8 gr, invert sugar 24.9 gr, baking soda 3 gr, ammonium bicarbonate 3 gr, lecithin 3 gr, egg 24.9 gr and different substitution levels 25, 50 and 75 (%) of erythritol that was substituted with sugar in the mentioned formulation. Biscuits were produced according to Vatankhah et al. (2014). Biscuits were analyzed for color indices (Francis, 1998), moisture, ash, sugar, weight and volume (Lin, Hwang and Yeh, 2003) and aw content (Zoulias, Piknis and Oreopoulou, 2000). Textural attributes (Savitha and Indrani, 2008), sensory properties (using hedonic scale) and density of product were also evaluated.
Results and discussion: According to the results obtained with increasing substitution level up to 25% aw content increased that the highest amount of aw between samples related to the one containing 25% erythritol. The preseason of lower aw content for control sample was due to the high hygrosopicity of sucrose (Wetzel, Weese and Bell, 1997). Increasing substitution level led to decrease in weight of samples. Decrease in weight of erythritol samples compare to control one is due to lower molecular weight of erythritol in compare to sucrose and other sugar alcohols. Results of volume analysis revealed that increasing in erythritol caused an increase in volume of biscuits. The highest amount was for 25% substitution and the lowest one related to control biscuit. This increase is related to texturizing and bulking agent of poly ols. Regarding the reverse relation between density and volume, lower apparent densities in higher volume samples seems to be ideal. According to the results moisture content increased with increasing the substitution level. Moisture content of a product is directly related to molecular weight, hydrophobic interactions, hydrophilic associations and the number of bonds (Rosell, Rojas and Benedito, 2001). Totally increasing in erythritol content in formulation did not affect ash content among biscuits and ash content didn’t significantly changed, which is due to similarity in oil and flour type and content (Pasha, Butt, Anjum and Shehzadi, 2002). As was expected sugar content of biscuits decreased with increase in substitution level, that the highest sugar content accounted for control sample and the lowest amount was for the sample containing 75% erythritol. Decrease in colour attributes of biscuits produced with erythritol in decrease in L* indices was related to not incorporation of poly ols in Maillard browning reaction and or caramelization reactions as well due to lack of carbonyl groups (Ronda, Gomez, Blanco and Caballero, 2005). Findings of statistical analysis related to textural attributes was demonstrating the decrease in the textural parameters by increasing substitution level in biscuit formulation that led to improve in texture of biscuit samples. Texture hardness is highly related to bonding ability of water in sugar alditols and it’s retaining during storage and also the interactions of these sugars with starch that may affect to starch retrogradation (Ronda, Gomez, Blanco and Caballero, 2005). Also, presence of alditols created a smoother texture that is highly related to more bonding with water (Ronda, Gomez, Blanco and Caballero, 2005). Results of overall acceptability revealed that biscuits substituted with erythritol obtained higher scores through sensorial properties.
Conclusion: Therefore, it can be claimed that erythritol can be used in biscuit formulation as a suitable sugar substitutes. Furthermore, sucrose substitution with this alditols will lead to a conspicuous decrease in total sugar content of samples, and lead to improvement in sensorial properties and textural attributes of biscuits compare to the control ones. So this alditols can be suggested to be used as a sweetener and profit flavoring agent in biscuit formula