Probing the storage stability and sensorial characteristics of wheat and barley grasses juice

Abstract The present research study was designed for the development of functional drinks from wheat and barley grasses followed by their physicochemical and sensorial characterization. In 1st phase, wheatgrass and barley grass juices were prepared with different concentrations and were subjected for physicochemical analysis and sensorial evaluation. Moreover, these juices were analyzed for color indices, pH, acidity, and total soluble solids (TSS) during storage study at 0, 2, 4, and 6 days. Results showed that TSS and pH of juices were 1.321, 2.8900, 3.100, and 6.225, 6.032, 6.491 for T0, T1, and T2, respectively, whereas a slight decreasing trend in acidity was observed during storage. Furthermore, treatments and storage (days) showed nonsignificant effect on these traits; however, storage affected significantly except for a* value for color indices. Conclusively, with respect to sensory aspects, the cereal grass juices showed satisfactory indexes of acceptability and promising marketing potential.

constituents of green grasses. The most notable quality of the green grasses juice is its high chlorophyll content which is involved in regeneration of blood or acts as substitute of hemoglobin in case when deficiency of hemoglobin occurs. Lifestyle-related disorder like anemia can be cured by the powerful effectiveness of green grasses (Padalia, Drabu, Raheja, Gupta, & Dhamija, 2010;Zeng et al., 2018). Green grass juices is one of the best magnificent drink which is involved in prevention and cure of cancer, HIV, hypercholesterolemia, diabetes owing to its strong anti-oxidant potential (Parit, Dawkar, Tanpure, Pai, & Chougale, 2018). These are also used in detoxification of pollutants and improving the Hb level because of its blood building capabilities and protection from solar and other types of radiation, also boosting energy and immunity (Singh, Pannu, Singh, & Singh, 2010). Cereal grasses contain considerable amount of Ca, Co, Fe, Mg, K, Zn, β-carotene, folate, pantothenic acid, vitamins B1, B2, B6, C, and E, SOD, catalase, and chlorophyll (Chand, Vishwakarma, Verma, & Kumar, 2008) (Figure 1).
Cereal grass juice contains ascorbic acid, which is seven times wealthier than an equal mass of citrus, five times better off in Fe than spinach, ten times wealthier in Ca than milk, is an important supply of vitamin cyanocobalamine, and contains 15 times as much protein as an equivalent quantity of milk. Green grasses juice is rich in vitamin K, which causes blood to clot (Rana, Kamboj, & Gandhi, 2011). Keeping in view the therapeutic role of green grasses against lifestyle-related disorder, that is, anemia, present project was designed to prepare the functional drinks from locally grown green grasses and to analyze this product for physicochemical properties and sensorial characteristics.

| Procurement of raw materials
Commercially available barley and wheatgrasses were procured from Wheat Research Institute, Ayub Agriculture Research Institute (AARI), Faisalabad.

| Sample preparation
Wheat and barley grasses were taken in a petri dish and then were placed in a hot air oven to dry the moisture content. After drying, grinding was done in the grinder with a sieve size of 6 mm. After grinding, wheat and barley grasses were again taken in a petri dish.
In the end, it was placed into a hot air oven to lower the chances of air contact and humidity.

| Product development
Fresh grass (wheat and barley) was grounded in a laboratory mortar and the juice was squeezed out through four layers of wet muslin cloth. The residue was twice resuspended in water and similarly squeezed. The filtrate was made up of the final volume with sterile water (Chin, Balunas, Chai, & Kinghonn, 2006) (Table 1).

| Physicochemical analysis
Cereal grasses juices were analyzed for the following characteristics.

| Color
The color of juices was estimated through CIE-Lab Color Meter (CIELAB SPACE, Color Tech-, PCM, USA). For the experiment, 5 ml of each respective juice was taken and color values like a* (−a greenness; +a redness), b* (−b blueness; +b yellowness) and L* (lightness) were recorded. The data obtained were used to compute chroma (C*) and hue angle following the method of Duangmal, Saicheuaa, and Sueeprasan (2008).

| pH
The representative juices were taken in 50 ml beaker and pH was recorded by pH meter (Ino Lab 720, Germany) following the method of AOAC (2006).

| Acidity
The acidity of barley and WGJs was determined during storage by adopting the guidelines of AOAC (2006). The selected sample was titrated against 0.1 N sodium hydroxide (NaOH) solution until persistent pink color.

| Sensory evaluation of product
The cereal grass juices were rated using a 9-point hedonic score system (9 = like extremely; 1 = dislike extremely) by trained taste panel (Meilgaard, Civille, & Carr, 2007). They were asked to express their opinion about the end product by giving a score to attributes like color, flavor, taste, texture, and overall acceptability. During the sensorial evaluation, juices with different grass concentration were placed in transparent cups, labeled with random codes. Cold water and crackers were supplied to panelists for rinsing their mouths between the samples. In each session, panelists were seated in separate booths equipped with white fluorescent lighting in an isolated room.

| Storage study
Physicochemical attributes like L*, a*, b*, acidity, pH, chroma, hue, and TSS of the resultant cereal grass juice treatments were carried out at 0, 7, 14, and 21 days of storage according to their respective protocols as mentioned above.

| Statistical analysis
The obtained data will be subjected to randomized design (CRD) using Statistical Package (Statistix 8.1). Levels of significance will be determined (ANOVA) using 2-factor factorial CRD following the principles outlined by Steel, Torrie, and Dikey (1997).

| Physicochemical analysis
Mean values regarding acidity, pH and TSS of different treatments of cereal grasses juices have been depicted in Table 2. These values The results are in accordance with Rexhepi and Renata (2015) who studied the pH values of wheatgrass, barley grass, and oat grass and stated that these values were varied from the lowest pH 3.31 for sample 2A (BGJ 30% and apple juice 70%) to 6.43 for sample no1 that is WGJ 100%, also stated that the pH of BGJ is lesser than that of WGJ.

| Color
Mean values exhibited that the color score of juice prepared from barley grass was 5.92 ± 0.62, 6.98 ± 0.41, 7.72 ± 0.81, and 7.19 ± 0.81, respectively, for T 0 , T 1 , T 2 , and T 3 . A maximum score of color (6.85 ± 0.56) in juice prepared from wheatgrass was recorded in T 2 and the minimum color score (5.92 ± 0.62) was observed in T 0 . Moreover, color scores of juice prepared from a combination Note. T 0 , acts as control.
of both barley grass and wheatgrass were observed as 5.92 ± 0.62, 5.63 ± 0.52, 6.00 ± 0.76, and 5.88 ± 0.64 for T 0 , T 1 , T 2 , and T 3 , respectively. Best juice color was observed prepared with barley grass, followed by wheatgrass and lastly a combination of both cereal kinds of grass. Level of cereal grass used (100 g) was most effective among all treatments (Table 3).

| Sourness
Mean values exhibited that the sourness score of juice prepared from barley grass was 5.98 ± 0.63, 6.11 ± 0.64, 6.51 ± 0.75, and 6.01 ± 0.01, respectively, for T 0 , T 1 , T 2 , and T 3 . A maximum score of sourness (7.78 ± 1.11) in juice prepared from a combination of both kinds of grass (Wheatgrass + barley grass) was recorded in T 2 and the minimum sourness score (5.98 ± 0.63) was observed in T 0 . Moreover, sourness scores of juice prepared from wheatgrass were observed as 5.98 ± 0.63, 6.12 ± 0.49, 6.89 ± 0.70, and 6.41 ± 0.54 for T 0 , T 1 , T 2 , and T 3 , respectively. Best juice was observed prepared with barley grass, followed by wheatgrass and lastly a combination of both cereal kinds of grass. Level of cereal grass used (100 g) was most effective among all treatments (Table 6).

| Overall acceptability
Mean values exhibited that the maximum overall acceptability score was recorded in juice prepared from barley grass was 6.15 ± 0.71, 6.78 ± 0.65, 7.69 ± 1.11, and 7.11 ± 0.62, respectively, for T 0 , T 1 , T 2 , and T 3 . A maximum score of overall acceptability (7.69 ± 1.11) in juice prepared from barley grass was recorded in T 2 and the minimum overall acceptability score (6.15 ± 0.71) was observed in T 0 . Moreover, overall acceptability scores of juice prepared from a combination of both barley grass and wheatgrass were observed as 6.15 ± 0.71, 6.22 ± 0.51, 6.32 ± 0.73, and 5.89 ± 0.11 for T 0 , T 1 , T 2 , and T 3 , respectively.
Best juice was observed prepared with barley grass, followed by wheatgrass and lastly a combination of both cereal kinds of grass.
Level of cereal grass used (100 g) was most effective among all treatments ( Table 7).
The results for sensory attributes are somehow in accordance with Rexhepi and Renata, (2015) who studied and evaluated sensory characteristics and consumer acceptance of green juices extracted from wheatgrass, barley grass, and oat grass, as well as their formulations with apple juice.

| Storage study
Barley grass juice and WGJ were developed and analyzed for following characteristics like color indices, pH, acidity, and TSS during storage study at 0, 2, 4, and 6 days. Treatments and storage (days) showed the non significant effect on these traits; however, storage affected significantly except for a* value for color indices.

| Color indices
A color indices test was done to determine the quality and consumer acceptance of the juices. Color measurement is mostly performed with the CIE-LAB color system and its attributes are L*, a* b*, chroma  Mollov, Mihalev, Shikov, Yoncheva, and Karagyozov (2007) supported the present findings as they reported a decrease in L* value of beverage (Tables 8-12).

| pH
Mean values regarding pH value of cereal grass juices ranged from 6.62 ± 0.47% to 7.63 ± 0.53%. The results showed that the maximum pH (7.63 ± 0.53%) was found in T 2 (WGJ) while, the minimum (6.043) was reported in T 1 (BGJ). A marked increase in pH of cereal grass juices was observed from 6.043 in T 2 containing BGJ to 6.181 in T 0 and 6.396 in T 2 containing WGJ. During storage, values for pH increased from 6.181, 6.211, 6.241, and 6.269 for T 0 at 0, 7, 14, and 21 day of storage, similarly, the same trend was observed in T 2 from 6.396, 6.560 at 0 and 4 day but this value decreased at the end of storage study from 6.560 to 6.460. Interactive effect of treatment and storage revealed that highest pH was recorded in T 2 (6.560) at the 7th day of storage period that decreased to 6.550 at the end of storage. Means values depicted a decreasing tendency for pH with the passage of time from 0 to 21 days of storage study for T 1 .
The results are in accordance with Rexhepi and Renata (2015) who studied sensory attributes and consumer acceptance of cereal grass juices extracted from wheatgrass, barley grass, and oat grass and their formulations with apple juice and found that the pH values of samples vary from the lowest pH 3.31 for sample 2A (BGJ 30% and apple juice 70%) to 6.43 for sample N0.1 that is WGJ 100%, also stated that the pH of BGJ is lesser than that of WGJ. The juices involved in this research were also assessed for pH, TSS and acidity because of their direct interference in sensory attributes of juices (Table 13).

| Acidity
Mean values regarding acidity of cereal grass juice characteriza- and acidity and observed that the acidity of BGJ is lighter than that of WGJ (Table 14).

| Total soluble solids
The mean values regarding TSS of cereal grass juices characteri- These results are compatible with earlier findings reported by Rexhepi and Renata (2015) who found TSS of the green juices ranged from 1 to 3.5. However, a higher percentage of TSS were found by Waghray et al. (2012) who evaluated appearance, aroma, taste and overall acceptability of WGJ for consumer acceptance to support the development of fresh juices and nutritional advantages of fresh vegetables to meet the needs of modern consumers, who increasingly buy ready to cook food or junk food to save time, without knowing that it is not a healthy diet. Carrot, wheatgrass, and bitter gourd juices were assessed for the total moisture content, total solids, TSS, and sensory analysis and analyzed that TSS of WGJ (with little addition of lemon juice) were 5.6-5.7 (Table 15).

| CON CLUS ION
Barley grass showed good hedonic response and storage stability. In the nutshell, utilization of these cereal grass juices in juice industry can fulfill multifarious objectives including maintaining good health of the consumer. These active ingredients also hold functional properties that are important for the juice industry. However, their contributions should be studied in order to enhance the meticulousness.
Cereal grass juices should be encouraged as a functional beverage in diet based therapies against different lifestyle-related disorders.
Insufficient data are available regarding the chemical analysis of BGJ, so focus should be made and further research must be performed on this parameter.

ACK N OWLED G M ENTS
The authors are thankful to Government College University Faisalabad and National Institute of Food Science and Technology and Higher Education Commission of Pakistan.

CO N FLI C T O F I NTE R E S T
Authors declare that they have no conflict of interest.

E TH I C A L S TATEM ENT
This article does not contain any studies with human participants or animals performed by any of the authors. It is further certified that human and animal testing is unnecessary in this study.

I N FO R M E D CO N S E NT
For this type of study, formal consent is not required.