Study on sensory evaluation of whey-based beverage using mulberry and peach juice

Introduction

The dairy industry is one of the largest food industries worldwide. In the dairy industry, a significant volume of whey is generated during the paneer manufacturing process. In local sweetmeat production units in India, a huge amount of whey is not processed for preservation and is discarded locally, which increases the BOD level of wastewater. Whey is not only a good source of protein, but it is also significantly rich in minerals and lactose. Whey and casein are the two main proteins present in milk. During the manufacture of paneer, casein coagulates to form the cheese curd, while milk fats become entrapped within the casein complex. The remaining liquid components, including whey proteins, minerals, and lactose form the liquid whey byproduct. Although the whey that is released is approximately 90% water and contains only about 0.6% protein, processes such as ultrafiltration and ultracentrifugation can convert raw liquid whey into whey concentrate, which contains about 90% protein (Huffman, 1996) [6] . Whey, the yellow-green fluid component of milk also known as paneer serum, is produced during the coagulation of milk with proteolytic enzymes or acids after the curd has been separated. Due to disposal difficulties caused by its high biological oxygen demand and high organic content, it was long regarded as a significant dairy waste product for www.extensionjournal.com many years (Esfanjani et al., 2015) [4] . Whey proteins are currently used for their bioactive components and are acknowledged as a viable nutritional source. Whey has a substantial connection to the dairy sector and is employed in a numerous commercial food products due to its rich nutritional profile. Whey proteins have gained immense popularity due to their exceptional nutritional value and significance in human nourishment. Numerous studies conducted over the past decade have underscored their indispensable role in the human diet. According to a joint technical report published by the Food and Agricultural Organization (FAO) and the World Health Organization (WHO) in 1985, whey proteins possess high digestibility and comprise a complete protein profile. The superior nutritional quality of whey proteins can be attributed to their elevated concentration of essential amino acids such as lysine, tryptophan, isoleucine, and threonine. This results in a higher Protein Efficiency Ratio (PER) for whey proteins (3.2) compared to casein (2.6) (Kumar et al. 2018) [7] . Whey's chemical composition varies depending on the processing method used to produce it (Minj and Anand, 2020) [9] . Mulberry-mulberry is a plant under family moraceae and genus morus. Mulberries contain iron, vitamins, protein etc. eating them may help reduce cholesterol, blood sugar and cancer risk. Morus nigra is commonly known as black mulberry, shatut (India), kara dut (Turkey) and shah-toot (Iran). Peach: Peaches are consumed fresh or canned, with yellowfleshed peaches being especially rich in vitamin A. Peach juice is a sweet, nutrient-dense beverage extracted from ripe peaches. Because peaches contain high amount of pulp, the juice is often processed as a puree to retain its signature smooth texture and fibre. It is widely valued for its antioxidant properties and high vitamin content.

Chemical composition of black mulberry

Material and Methods

Materials

Mainly included the ingredients required for optimization of compositional and processing parameters of whey beverage with different fruit juices. The following material were used for the present investigation.

Whey: Fresh whey was collected after preparation of paneer in the Department of Animal Husbandry & Dairying, Chandra Shekhar Azad University of Agriculture and Technology, Kanpur. The whey was collected in a clean, sterilized stainless steel bucket while taking all necessary hygienic precautions. Sugar: Commercial grade white crystalline cane sugar was used as a sweetening agent, which was obtained from the local market in kanpur city. It was ensured that the sugar was free from dust, dirt and other foreign impurities.

Milk vessels: All the vessels used for the processing and preparation of whey drink thoroughly cleaned manually before using in the laboratory.

Mulberry and peach fruits: Ripe fruits of mulberry (M. nigra) were harvested from trees in horticulture garden of C S A University, Kanpur. A good quality peach fruits was obtained from the market after ensuring their market quality.

Glass wares:

The beaker and measuring cylinder with a capacity of 500 ml. and 250 ml, respectively were used for standardization of whey. Vessels, butyrometer, pipettes, automatic tilt measures lock stopper etc were properly cleaned before use.

Muslin cloth:

To remove visible dirt, dust and foreign matter from the whey was strained through a fresh muslin cloth.

Equipment:

The following equipment was used for the preparation of chhana whey included a gas stove, muslin cloth, stainless steel pan, stainless steel ladle, stainless steel plate and a stainless steel knife

Methods Preparation of mulberry and peach juice a1) Mulberry fruits (Morus nigra)

The mulberry fruits were initially washed thoroughly with potable water to remove any surface impurities. After washing, the juicing process broke down the arils, releasing the vibrant, ruby-red mulberry juice. To ensure clarity, the extracted juice was passed through a sterile muslin cloth, which helped to filter out the seeds and remaining pulp. The filtered juice was collected in a clean, transparent glass bowl, ensuring a pure and smooth consistency.

a2) Peach juice (Prunus persica)

The preparation of peach juice began with the thorough washing and rinsing of fresh peach fruits using potable water to ensure cleanliness and hygiene. After washing, the fruits were peeled using a sterile stainless-steel knife to remove the outer skin. The peeled peach fruits were then cut into small pieces using the knife. These pieces were placed into a clean electric blender for homogenization. The blending process helped to extract the juice efficiently, ensuring a smooth consistency. The homogenized juice was then filtered through a sterile muslin cloth to remove any remaining pulp or solid particles.

Examination of whey drink Sensory evaluation

A panel of five Judges conducted the sensory evaluation of the beverage samples. According to Maroney (1975) [14] , samples were graded using a 9-point hedonic scale. The samples were assessed for sensory factors, such as flavor, colour and appearance, sweetness and overall acceptability. Evaluation form for the numerical test of beverage quality attributes the samples were scored for quality aspects using the grade description and scoring system describe below.

Result and Discussion

The present investigation entitled "Study on Sensory Evaluation of Whey based Beverage using Mulberry and Peach Juice" was carried out in the Department of Animal Husbandry and Dairying, Chandra Shekhar Azad University of Agriculture and Technology, Kanpur. In order to evaluate the effects of different factors like two types of fruit juices (mulberry juice-A1, peach juice-A2), four levels of juices (10 percent-B1, 20 percent-B2, 30 percent-B3 and 40 percent-B4), three sugar levels (5 percent-C1, 10 percent-C2, 15 percent-C3) and four storage periods (0 Day-D1, 10 Days-D2, 20 Days-D3 and 30 Days-D4) on sensory attributes (flavour, colour and appearance, sweetness and overall-acceptability). The experimental data was analyzed using a factorial experiment in Completely Randomized Design (CRD). The results and their interpretations for various attributes are discussed systematically below.

Sensory quality 3.1 Flavour

The flavour of a fruit juice based whey beverage is one of its most important quality attributes and should be free from any off flavours. Excessive acidity and curdling are undesirable characteristic in a whey based beverage. It must also be free from foreign material, bitterness, saltiness or any other off flavour. The flavour profile of the fruit juice based whey beverage as affected by different experimental factor (A, B, C & D) is presented in Table 4 with critical difference shown in Table 5. These tables and figure no. 1 revealed the following facts. [8] reported flavor score for whey beverage in the ranges of 6.5 to 7.83, while Gupta et al. (2014) [5] reported flavor score for fruit based carbonated whey beverages ranging between 6.8 to 7.8.

From Table 4 representing the interactions between the type of fruit juices and different levels of fruit juices (A×B), it was observed that the fruit juice based whey beverage prepared from mulberry fruit juice with 30% fruit juice (A1×B3) showed the maximum score (8.200), while the minimum flavour score (6.100) was noted in A2×B4 sample.

Regarding the effect of treatment combinations of the type of fruit juice and different levels of sugar (A×C), the maximum flavour score (7.090) was observed when the sample was prepared with mulberry fruit juice and 10% sugar (A1×C2), followed by A1×C3 with a score of 6.970 and A2×C2 with a score of 6.960, while the minimum flavour score (6.800) was noted in the A2×C4 sample.

From the interaction between fruit types and storage period (A×D), the highest flavour score (8.140) was recorded in fresh samples prepared with mulberry fruit juice (A1×D1).

The next highest flavour score (8.110) was recorded in the samples prepared with peach fruit juice (A2×D1).

From the interaction between juice levels and sugar level (B×C), the highest flavour score (7.154) was occurred in the sample prepared with 30% fruit juice and 10% sugar (B3×C2), followed by B2×C2 and B4×C2, while the minimum score (6.685) was obtained in the B1×C1 sample.

From the interaction between sugar levels and storage period (C×D), the maximum flavour score (7.762) was recorded in the fresh sample prepared with 10 % sugar level (C2×D1), and the minimum score (6.491) was obtained from C3×D4 sample. The results recorded in the present investigation for flavour were comparable with the findings of Prasad et al. (2001) [11] , who prepared a whey-based mango beverage and noted an average sensory score for flavour in the range of 6.23 to 8.76.

Colour and appearance

The colour and appearance of fruit juice based whey beverage should be pleasing, attracting and uniform, without showing any sign of visible foreign matter. The colour of whey beverage prepared from mulberry juice ranged from bright red to red and the colour of whey beverage prepared from peach juice ranges from bright yellow to yellow. The effect of different factors on colour and appearance is presented in Table 6 and Critical Difference From Table 6, which presents the mean values for the different levels of all factors, the following observations were made: The highest colour and appearance score (7.383) was observed in the beverage sample containing A1 (mulberry juice) at the B3 juice level, while the minimum score (6.822) was recorded in the A2 (peach juice) sample.

The colour and appearance score showed an increasing trend with higher levels of juices in whey beverage.

Regarding the effect of different sugar levels (C) on the colour and appearance score of fruit juice based whey beverage, the highest score (7.269) was observed in C1 (5% level of sugar) samples, followed by C2 (10% sugar), while the minimum score (7.06) was noted in C3 (15% sugar) sample.

Evaluating the effect of storage periods (D) on the colour and appearance of fruit juice based whey beverage, the fresh sample (D1) achieved the highest score (7.727) followed by (D2). Conversely, the lowest score (6.61) was recorded at 30 days of storage (D4). As the storage period increased, the colour and appearance quality of product decreased, indicating that quality deteriorated over time.

Regarding the interaction between fruit juice type and storage period (A×D), the highest colour and appearance score (7.772) was observed in fresh mulberry juice samples (A1×D1). Followed closely by fresh peach juice samples (A2×D1) with a score of 7.683. Conversely, the lowest score (6.538) was found in A2×D4.

For the interaction between juice levels and sugar levels (B×C), the maximum colour and appearance score (7.387) was observed in sample prepared with 30% fruit juice and 5% sugar (B3×C1) followed by B3×C2 whereas the minimum score (6.758) was occurred in sample B4×C2 (40% fruit juice and 10% sugar).

Regarding the interaction between juice levels and storage period (B×D), fresh samples with 30% fruit juices (B3×D1) achieved the highest score (7.866) while the minimum colour and appearance score (6.483) noted in B4×D4 sample.

Similarly, for the interaction between sugar level and storage period (C×D), the highest colour and appearance score (7.800) was observed in fresh sample prepared with 5% sugar (C1×D1) whereas the lowest score (6.512) obtained in sample from C3×D4. www.extensionjournal.com

Sweetness

The sweetness of the fruit juice based whey beverage should be pleasing. The effects of various factors (A, B, C & D). on sweetness are presented in Table 8 and its Critical Difference Table 9. Furthermore, the data shown in Figure no. 3 reveal the following key finding. From Table 8 evaluating the interactions between type of fruit juices and different levels of fruit juices (A×B), the sample prepared from mulberry fruit juice with 30% level of fruit juice (A1×B3) showed the maximum sweetness score (7.277), while the minimum sweetness score (6.752) was noted in A2×B4 sample. Among the treatment combination of type of fruit juices and different levels of sugar (A×C), the maximum sweetness score (7.318) was observed in samples prepared with 10 % mulberry fruit juice and 10 % levels of sugar (A1×C2) and the minimum sweetness score (6.766) was noted in A2×C3 sample.

Evaluating the interaction between type of fruit juices and storage period (A×D), the highest sweetness score (7.808) was recorded in fresh samples prepared with mulberry fruit juice (A1×D1), while the lowest sweetness score (6.477) was found in A2×D4.

From interaction between different levels of fruit juices and sugar levels (B×C), the maximum sweetness score (7.525) was observed in sample prepared with 30% level of fruit juice and 10% level of sugar (B3×C2), and the minimum score (6.591) obtained in sample prepared with 40% level of fruit juice and 15% sugar level (B4×C3).

Evaluating the interaction between different levels of fruit juices and storage period (B×D), the highest sweetness score (7.761) was observed in fresh samples prepared with 30% level of fruit juice (B3×D1), while the lowest sweetness score (6.238) was found in B4×D4.

From the interaction between sugar levels and storage period (C×D), it was observed that the maximum sweetness score (7.850) was recorded in fresh sample prepared with 10% level of sugar (C2×D1), and the minimum score (6.195) was obtained from C3×D4 sample.

Overall-acceptability

The overall acceptability of fruit juice based whey beverage as affected by different factors (A, B, C & D) has been presented in Regarding the effect of storage periods (D) on the overall acceptability score of fruit juice based whey beverage, the highest score (7.726) was obtained in fresh sample (D1) followed by D2. The lowest overall acceptability score (6.517) was observed in D4 sample. Overall acceptability score decreases with increasing storage duration. Furthermore, Table 10 shows the mean interactions between different types of fruit juices and their respective levels (A×B). Fruit juice based whey beverage prepared from mulberry juice with a 30% juice level (A1×B3) showed the maximum score (7.372), while the minimum overall acceptability score (6.891) was recorded in A2×B1 sample. Among the treatment combinations of different types of fruit juices and sugar levels (A×C), the maximum overall acceptability score (7.300) was observed in samples prepared with mulberry juice and 10% sugar (A1×C2), while the minimum overall acceptability score (6.814) was recorded in A2×C3 sample.

Regarding the interaction between fruit juice type and storage period (A×D), the highest overall acceptability score (7.769) was observed in fresh samples prepared with peach fruit juice (A2×D1).Closely followed by fresh samples prepared with mulberry fruit juice (A1×D1) with a score of 7.683. www.extensionjournal.com

For the interaction between fruit juice levels and sugar levels (B×C), the maximum overall acceptability score (7.466) was recorded in samples prepared with 30% fruit juice and 10% sugar (B3×C2) whereas the minimum overall acceptability score (6.762) was obtained in B4×C3 sample.

Regarding the interaction between fruit juice levels and storage period (B×D), the highest overall acceptability score (7.816) was recorded in fresh sample prepared with 30% fruit juice (B3×D1) while the minimum overall acceptability score (6.411) was noted in the B1×D4 sample.

Regarding the interaction between sugar levels and storage period (C×D), the maximum overall acceptability score (7.875) was observed in fresh sample prepared with 10% sugar (C2×D1) while the minimum score (6.325) was obtained in the C3D4 sample. These results are in line those reported by Aher (2007) who observed overall acceptability scores ranging from 7.31 to 7.95 for papaya whey beverage. similarly, Landge et al. (2013) [8] reported the overall acceptability score ranging from 6.61 to 7.50 for whey beverage. Gupta et al. (2014) [5] reported overall acceptability scores between 7.0 & 8.2 for fruit based carbonated whey beverage.

Conclusion

The data obtained from the sensory evaluation of whey drink, prepared from paneer whey-using different fruit types, juice levels and sugar concentrations-indicated that the overall acceptability of fruit juice-based whey drinks was found better in the sample prepared using paneer whey with addition of 30ml fruit juice and 10% sugar per 100ml drink.

Acknowledgement

AcknowledgementI am express my heartfelt gratitude to Dr. Ramjee Gupta, Professor, Department of Animal Husbandry & Dairying, Chandra Shekhar Azad University of Agriculture & Technology Kanpur, UP (208002), India. I am also deeply thankful to the Professor & Head of the Department of Animal Husbandry & Dairying, Chandra Shekhar Azad University of Agriculture & Technology Kanpur, UP (208002), India, for providing the necessary facilities, financial support and valuable guidance for this research work.

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