Sensory Optimization of Completely Grape Juice with Added Yam

Research Article

Austin J Nutri Food Sci. 2019; 7(7): 1130.

Sensory Optimization of Completely Grape Juice with Added Yam

Andrade AC1, Rodrigues JF2, Oliveira JPL1*, Natividade MMP1 and Bastos SC1

1Departament of Nutrition, Federal University of Lavras, Brazil

2Departament of Agrarian Science, Federal Institute of Minas Gerais, Brazil

*Corresponding author: Oliveira JPL, Department of Nutrition, Federal University of Lavras, Street Instituto, 440, Vila São Francisco, Lavras – MG, Zip code: 37200- 000, Brazil

Received: September 09, 2019; Accepted: October 16, 2019; Published: October 23, 2019

Abstract

Due to the possibility of adding yams to beverages, it is believed that the yam added to the whole grape juice will make it even more nutritious by raising the content of vitamins, minerals, and mainly antioxidant compounds, besides possibly obtaining a more creamy juice, i.e., with innovative technological characteristics. Therefore, the present study aimed to evaluate the effect of the addition of different yam concentrations on the sensory characteristics of completely grape juice. Juice formulations were evaluated through acceptance tests with 75 consumers. Two analyses were performed to evaluate the impact of the product health benefits information on the consumer acceptance. Based on the results of the sensory analysis, it can be concluded that it is possible to add up to 15% of yam in the completely grape juice without depreciating its sensory quality. This addition of yam to the juice can contribute favorably with the nutritional value of this beverage and hence with its sensory acceptance by the consumer. It was possible to observe that information and health concern by consumers contributed to increasing the product acceptability; however, the sensory properties are decisive to elaborate a new product.

Keywords: Grape juice; Health information; Yam; Beverages

Introduction

The population is now becoming more health conscious, but considering the current fast-paced life, people have been looking for practical, healthy foods, i.e., ready-to-eat or serve. This has led to the popularization of natural fruit juices as a healthier alternative in relation to other beverages and soft drinks with high sugar content [1].

Natural fruit juices are part of the daily diet of people of different age groups and provide a deep relationship with health due to its nutritional content, functional and therapeutic qualities. Its consumption is associated with the reduction of diseases such as cancer, neurodegenerative and cardiovascular diseases [1,2].

Grape is one of the most consumed fruits worldwide due to its sensory properties, commercial availability and reasonable price, besides showing relatively high yield. In this sense, grapes are widely used to obtain several products, including grape juice [3]. Grape juice is one of the primary grape derivatives and can be defined as an unfermented and undiluted beverage, obtained from the edible part of the grape (Vitis ssp.) through appropriate technological processes [4].

Grape juice has becoming relevant because it contains a high amount of bioactive compounds, mainly phenolics, such as anthocyanins, catechins, resveratrol, among others, which have antioxidant properties capable of providing health benefits, including prevention of cardiovascular diseases and cancer [5,6].

Changes in eating habits, besides sensory preferences of consumers, have contributed to emerging a new trend related to beverages prepared with fruits and vegetables. The blend of fruits and vegetables can improve sensory properties such as aroma and flavor, besides adding higher nutritional value to beverages. Therefore, the food industries are seeking to develop new juices with vegetables, such as with added yam [7].

Yam is a tuber with a good source of nutrients, being rich in vitamin C and thiamine, minerals (K, P, Ca, Mg, Fe and Cu), antioxidant fibers and compounds (phytosterols) [8,9]. Thereby, yam has potentially positive health effects and can increase the antioxidant capacity [10], acting as cardioprotective, anti-inflammatory and lipid metabolism, reducing the triglycerides and improving the cholesterol profile [11,12].

Besides providing potential health effects, the addition of yams may contribute with critical technological characteristics in product development due to its high starch content [11]. According to [13] Pelegrini and Carrasqueira (2008), yam juice is a much-valued product. These same authors prepared a vitamin yam juice and another of pineapple, and found that yam juice was the most preferred after sensory analysis [14]. Martins et al., (2011) also obtained good acceptability for a sports drink prepared from the concentrated juice of fruits and vegetables containing yams. This fact suggests that the addition of yams to beverages can improve sensory acceptability and contribute to the product’s nutritional value.

Due to the possibility of adding yams to beverages, it is believed that the yam added to the whole grape juice will make it even more nutritious by raising the content of vitamins, minerals, and mainly antioxidant compounds, besides possibly obtaining a more creamy juice, i.e., with innovative technological characteristics. Therefore, the present study aimed to evaluate the effect of the addition of different yam concentrations on the sensory characteristics of completely grape juice.

Material and Methods

Samples

Completely grape juice (Campino®) and yam (Dioscorea sp.) were used for the product processing. Raw materials were purchased in the Lavras commerce derived from a single batch.

Juice formulations were determined by preliminary tests, being established ratios of 5%, 10%, 15%, 20% and 25% of yams. According to previous assays, a yam addition greater than 25% mischaracterized the completely grape juice concerning taste, color and texture and therefore levels above this were avoided.

Yam was washed in running water in order to remove the larger soils, sanitized in sodium hypochlorite (NaClO) solution at 200 ppm for 30 min and thereafter washed in running water; afterward, it was peeled, cut in cubes and ground in a blender (Walita®) together with whole grape juice [14,15] (Martins et al., 2011; Rodrigues et al., 2015), for approximately 4 min until complete yam dissolution. The prepared beverages were submitted to the physical and chemical analyses and were placed in the refrigerator for approximately 2 h for temperature balance. After this period, the sensory tests were performed.

Sensory analyses

Sensory analyses were performed at the Sensory Analysis Laboratory of the Federal University of Lavras with healthy individuals and without any restriction to the analyzed products. The study was performed according to the Research Ethics Committee on Human Beings of the Federal University of Lavras (CAAE: 34331414.6.0000.5148).

Juice formulations were evaluated through acceptance tests with 75 consumers through SensoMaker software [16] (Pinheiro et al., 2013). Two analyses were performed. In the first analysis, the consumers did not obtain any information about the product (ingredients, benefits, among others). However, in the second test, previously to sensory analysis, a pamphlet was shown to each tester informing the ingredients and benefits of whole grape juice with added yam, such as sugar-free, water, preservatives and colorings, and the presence of fibers, minerals and antioxidants, besides their potential health benefits (prevention of chronic diseases, such as cardiovascular disease, improvement of cholesterol profile, reduction of triglycerides and other diseases associated with oxidative stress).

Four properties were evaluated: appearance, aroma, taste and overall impression. To this end, the tasters were instructed to taste the samples from left to the right and indicate how much they liked or disliked each one, using a structured 9-point hedonic scale, which ranged from “1-dislike extremely” to “9-like extremely” [15,17] (Rodrigues et al., 2015; Minin, 2010), and a structured five-point Likert scale, which ranged from 1 “certainly would not buy” to 5 “buy certainly” for the purchase intention.

In both sensory tests, grape juice samples (30 ml) without and with yam were served to the tasters. They were served in disposable white plastic cups, identified by three-digit numbers arranged in a balanced order, according to Wakeling and McFie [18] (Wakeling and McFie, 1995). Evaluations used white light. The tests were performed in individual cabins, at room temperature, with adequate lighting and without the interference of odors and noise [19] (Bowles and Demiate, 2006).

Statistical analysis

Sensory results were evaluated through analysis of variance and Tukey test, and through internal preference mapping, using Sensomaker software [16] (Pinheiro et al., 2013). Physical and chemical data were expressed as the triplicate average and the respective standard deviation.

Results and Discussion

Sensory analysis

The results of acceptance tests (with and without information on the product benefits) were evaluated by three-way preference mapping (Figure 1A and 1B).

Citation: Andrade AC, Rodrigues JF, Oliveira JPL, Natividade MMP and Bastos SC. Sensory Optimization of Completely Grape Juice with Added Yam. Austin J Nutri Food Sci. 2019; 7(7): 1130.