Textural Characterization of Dietetic Amrakhand Prepared by using Stevia Leaf Extracts Powder

Amrakhand is an Indigenous fermented and sweetened milk product of Indian origin, is very popular in Maharashtra and Gujarat. Amrakhand is thick, creamy and has a smooth consistency. It has pleasant yellow color, sweet in taste and has mango flavor with sourness of yoghurt. Mango and mango flavored products has great acceptance by consumers mainly due to its sweet and flavor characteristics (Rehman, 2003; Bowden, 2007; Barnett et al., 2008). 
 
Amrakhand is prepared by blending chakka (strained dahi/curd) sugar, fruit pulp, cream and other ingredients like nut, flavor, spices, colour etc. Now a day’s growing interest in the diversification of this functional product attract wide range of consumers. In the recent past years it is noticed that many attempts made to incorporate different fruit pulps and additives such as mango pulp (Bardale et al., 1986), cocoa powder with or without papaya pulp (Vagdalkar et al., 2002), strawberry pulp (Sonwane et al., 2007), ashwagandha powder (Landge et al., 2011) and apple pulp with celosia powder (Kumar et al., 2011) in shrikhand.
 
With the changing food style, diseases like obesity, diabetes and cardiovascular have become major concern worldwide. The production of sugar free product enables diabetic people to relish the dairy product without affecting their blood glucose level. Further the trend of low fat and low sugar food is spurred by calorie conscious section of the modern society. In this context various low calorie sweeteners and zero calorie sugar replacers have been used in formulating traditional Indian dairy products thereby replacing sugar either partially or completely, such as aspartame in dietetic and diabetic rasogolla (Jayprakash et al., 2003), aspartame, sucralose and stevia in basundi (Goel, 2008), aspartame and sucralose in burfi (Prabha, 2006). However stevia reduces blood sugar level and doesn’t affect the metabolism of insulin (Kinghorn, 2002). Good sensory score was observed while replacing 70% of sucrose by powdered stevia leaf extract in dietetic Amrakhand (Tondare and Hembade, 2019). Therefore, stevia leaf extract powder is used for preparation of dietetic Amrakhand. Textural characterization of product is valuable in process development studies. As food texture is the way in which various constituents and structural elements are arranged and combined into a microstructure leading to a macrostructure, external manifestation of flow and deformation. Keeping these in mind, evaluated the effect of powdered stevia leaf extract on textural properties of dietetic Amrakhand.

Ingredients
 
Fresh buffalo milk, good quality cane sugar and Alphonso mango pulp of ‘Chitale’ brand was purchased from local market. Refined Stevia leaf extract powder (containing 97% Rebaudioside A) was purchased from Stevia world Agro Tech. Pvt. Ltd. Bangalore, Karnataka, India. 1 gm of refined stevia leaf extracts powder is equals to approximately 200 gm of cane sugar. The study was carried out at Department of Dairy Science, Yeshwant Mahavidyalaya Nanded during February 2019 to March 2020.
 

 
Production of dietetic Amrakhand
 
Amrakhand was prepared by using fresh, pasteurized buffalo milk with 6% fat and 9% solids not fat in a known quantity. Milk was heated at 85°C for 30 minutes, followed by cooling at 28°C. It was then inoculated @ 2% with locally available starter culture, which is mixed well and incubated at 35°C for 8 hours. When the curd has set firmly it was broken and placed in muslin cloth and pressed for expulsion of whey for 6 hours, the semi solid mass thus obtained was Chakka, form the base for shrikhand (De, 2009). As depicted in Table  2 at 27°C chakka was admixed with six different treatment combination of sucrose: stevia leaf extract powder viz. 30:70 (T₁), 25:75 (T₂), 20: 80 (T₃), 15:85 (T₄), 10:90 (T₅) with control sample 100:0 (T₀). Alphonso mango pulp was added at the rate of 30% (30 gm) per 100 gm of Chakka.
 

 
Textural characterization
 
A texture analyzer (TA-XT2I, Stable Micro System, UK) was used to determine the textural characteristics viz., hardness, consistency, index of viscosity and cohesiveness of the dietetic Amrakhand. The analysis was carried out at 23°C. For each parameter three replications were taken by using a 25 mm stainless steel cylindrical probe (P25). The penetration depth at the geometrical center of the sample was 10 mm and the penetration speed was set at 1 mm/s. space.
 
Statistical analysis
 
Data analyzed statistically by one way ANOVA using WASP web based agricultural statistics software package developed by ICAR-Central Coastal Agricultural Research Institute, Goa-403 402, India.

Effect of stevia leaf extract powder on textural properties of dietetic Amrakhand
 
Firmness
It is peak compression force (N), a soft product is one that displays a slight resistance to deformation and a firm product describes one that is moderately resistant to deformation and hardness that describes a product which displays substantial resistance to deformation, firmness value of all the sample was decreased with increased level of stevia leaf extract powder, i.e. From 1.27 N to 1.21 N respectively as compared to control sample containing 100% sugar 1.28N, it might be due to compositional differences which produces variation in microstructure as amount of sugar content reduced, which leads to increase in moisture content. Also addition of mango pulp increases the softness of Amrakhand.
 
Mehrotra et al., (2013) found in TPA of low-calorie Shrikhand prepared by using stevia leaf powder showed hardness value decreases with decrease in amount of sugar. The decreasing trend was in the pattern of 65.1g (10% replacement), 64.1g (20% replacement), 63.2g (30% replacement) and 62.2g (40% replacement) against control product was 66.1g. These results are comparable with the results of present study.
 
Consistency
 
Consistency analysis showed a significant difference with the addition of stevia leaf extract powder. The consistency value of dietetic Amrakhand decreases with substituting sucrose with stevia leaf extract powder in the pattern of T₁ (9.83 Ns), T₂ (9.59 Ns), T₃ (9.49 Ns), T₄ (9.48) and T₅ (9.30 Ns), as compared to control T₀ (11.45 Ns).  With increasing proportion of stevia leaf extract powder, dietetic Amrakhand loses its thickness, higher value indicate a more viscous or thicker sample, consistency relates to the firmness, thickness or viscosity of liquid or fluid semi-solid. Stirring a fluid or semi-solid fluid with a spoon or a finger is frequently used by consumers to an indication of viscosity or consistency.
 

 
Cohesiveness
 
Cohesiveness is the tendency of a product to cohere or stick together. The intermolecular attractions by which the elements of the body or mass of material are held together determine its cohesiveness (Nasaruddin et al., 2012).
 
Mean cohesiveness value of dietetic Amrakhand decreases from -1.97 to -1.34N by replacing 70 to 90% against control -2.14N by 0% replacement of sugar. Decrease in amount of sugar showed that the cohesiveness value of product decreases compared to control sample. It may be due to an addition of mango pulp. Pon et al., 2015 revealed that replacement of sugar with stevia in different concentration, there was significant increase in cohesiveness of ice-cream.  
 
Index of viscosity
 
Mean Index of viscosity value in terms of Ns decreases from -1.34, -1.25, -1.02, -0.90 and -0.81 for T₁, T₂, T₃, T₄ and T₅ against -1.50 for T₀ (control) with increasing the concentration level of stevia leaf extracts powder. Though mango pulp increases the intermolecular attraction but stevia leaf extract powder might decreases the force required to withdrawal of probe from the product. Index of viscosity is the extrusion energy or work of adhesion where as it becomes higher; more resistance is required when pulling out the sample (Liu et al., 2007). These suggest that viscosity is very much related to resistance to flow and may be related to cohesiveness and consistency (Nasaruddin et al., 2012).

Thus in prepared dietetic Amrakhand decreasing trend was observed for each textural property with substitution of sugar by stevia leaf extract powder.
 
Sensory attributes
 
It was depicted in Table 4 that Sensory attributes color and appearance, flavor, Mouthfeel, body and texture, aftertaste and overall acceptability score was in the pattern of T₁>T₂>T₀>T₃>T₄>T₅, the treatment T₁ had best overall acceptability score over other treatments by the panel of judges. Treatment T₁ had highest overall acceptability score (8.00) than control (T₀) i.e. (7.82). (Tondare and Hembade, 2019).
 

 

 

 

 
The results are in line with the Kalicka et al., 2017 found that yoghurt with stevia considered worse, but yoghurt contains 75% addition of stevia in the mixture, was usually selected as a second choice. The present study was also in line with the Mehrotra et al., 2013 revealed that substitution of 30% of stevia leaf powder scored highest and the replacement of sugar by the powder, till 30% did not differ significantly from the control sample.

It is concluded that substitution of sugar with stevia leaf extract powder decreases the hardness, consistency, cohesiveness and index of viscosity values of dietetic Amrakhand. Dietetic Amrakhand containing 70% replacement (T₁) of sugar with stevia leaf extracts powder thrive better over other treatment combinations in terms of its textural characterization. Therefore minimum concentration of stevia leaf extracts powder can be adjudged to be formulated in the dietetic Amrakhand for calorie conscious section of the society.

The present study was carried out in the Laboratories of Department of Dairy Science, Yeshwant Mahavidyalaya, Nanded, affiliated to Swami Ramanand Teerth Marathwada University, Nanded with the support of head of the department.