Effect of Sensory Properties, Shelf Life and Cost of Production on Black Gram (Vigna mungo) Flour Burfi

Traditionally, burfi is prepared by vigorous mixing of khoa and sugar in open shallow kettle till a homogenous, smooth and fine grain mass appears and then it transferred hot into a tray for cooling and setting. “A good quality burfi, however, specialized by moderately sweet taste, white to light creamy colour with soft and slightly greasy body and smooth texture with very fine grains.” Sugar is added in different proportion depends on product prepared and other ingredients incorporated according to demand of the consumer. It is prepared by blending different proportions of khoa and specified amount of sugar along with some other ingredients like dry fruits, fruit pulps, different cereals and pulses with their flours and flavouring materials. Burfi has special importance in different functions like birthday, anniversary, wedding, to celebrate success in examination or in such other events. Burfi shows wide variation in Indian market depending upon the regional performance. Several varieties of burfi are sold in market i.e., plain or mawa burfi, cashewnut burfi, orange burfi, almond burfi, mango burfi, wood apple burfi, etc. Consumers in India are becoming more health conscious and demand for healthier food because of rise in disposable income, educational level and awareness of nutrition. Among the different additives which are used in burfi, pulses also play an important role in Indian market. In wedding ceremony, the recent trend is to prepare the besan burfi or chickpea burfi instead of laddu because of the nutritional importance of pulses. Different pulses like chickpea, moong bean, black gram are also used in diet through different dishes.
       
Pulses plays an important role in farming system throughout the world. Among the different pulse crops, black gram is important crop in India. Black gram (Vigna mungo L.) reported to be originated in India. India is the highest producer and consumer of black gram in world. Black gram (Vigna mungo L.) belongs to family Leguminoseae. It is a protein rich food. It provides a major share of protein requirement of vegetarians. The black gram contains 25.21 gm/100 gm proteins, 1.2 gm/100 gm fat, 56.6 gm/100 gm carbohydrate, calcium 185 mg/100 gm, ferrons 8.7 gm/100 gm, phosphorous 345 mg/100 gm (Pulse crops, IARI, New Delhi). The black gram beans are referred as ‘masha’ in the ayurvedic texts and highly recommended for gaining weight and improving immunity. Patients suffering from asthma, paralysis, constipation are recommended to include black gram in daily diet for its innumerable healing properties. It has many health benefits as-energy booster, improves digestion, keep heart healthy, anti-ageing, control diabetes, builds muscles, prevents kidney stones, promotes hair growth, reduces pain and inflammation, support bone health, strengthen nervous system, good for pregnant women (Kanade, 2006). Realizing the health benefits of black gram flour, it is decided to undertake this research project.

The research study carried out on “Studies on utilization of black gram (Vigna mungo) flour in preparation of burfi” taken at department of Animal Husbandry and Dairy Science, College of Agriculture, Vasantrao Naik Marathwada Krishi Vidyapeeth, Parbhani.
 
Materials
 
The whole, clean, fresh buffalo milk was obtained from market. Black gram flour, sugar obtained from local market. Different equipments viz., karahi, khunti, stainless steel trays, mixer grinder were available in the department.
 
Methods
 
The burfi with different combinations was prepared by addition of black gram flour in proportion of 2.5, 5, 7.5 and 10% of black gram flour in khoa.
       
Firstly, fresh clean buffalo milk was taken and filtered through muslin cloth to remove dust particles. Meanwhile, powdered black gram was roasted in other karahi at 50^oC for 5 minutes. This roasted powder was used at different trials during burfi preparation. Buffalo milk was standardized to 6 per cent fat. Then it was poured into iron karahi and started heating the milk. Continuous vigorous heating at 55-60^oC in open pan on gentle fire with continuous stirring cum scrapping was carried out with the help of stainless steel khunti. The milk was concentrated to pasty consistency by evaporating the moisture. When the product started to leave sides of karahi i.e., at pat formation stage (khoa), reduce the flame and add roasted black gram flour as per the treatments and sugar @ 30 per cent by weight of khoa was added and properly mixed. Heating and stirring at low flame were carried out till the desired textured product was obtained. Then the mixture was transferred into greasy stainless steel tray, spread it and allow it for cooling. After setting, burfi was cut into square shape. The following method was used as per Sharma et al., (2017) with slight modifications:
 

Sensory evaluation of black gram flour burfi
 
The different treatment combinations of burfi were subjected to sensory evaluation of colour and appearance, flavour, body and texture, overall acceptability characteristics by a panel of judges using 9^th point hedonic scale.
 
Colour and appearance
 
The data presented in Table 1 indicated that, colour and appearance score for various treatments ranged between 7.58 to 8.50. This score for T₃ treatment was higher than rest of the treatments. The acceptable highest score was for T₃ (8.50) which has yellow brownish colour as compared to other burfi trials. The lowest score was for T₅ (7.58) with very dull appearance having 10 per cent black gram flour. Among the added levels of black gram flour, the highest score for general appearance was burfi having 5 per cent black gram flour with faint yellowish brown colour and appeared fresh whereas burfi obtained from 10 per cent black gram flour gave dark shades with totally dull appearance which was not liked so much by judges.
 

       

Jadhav (2015) experimented on besan burfi suggest that as the level of besan increases, acceptability of burfi decreases because besan imparts dark, uneven, dull appearance. Khapre (2015) recorded colour and appearance score for fig fruit powder enriched burfi ranging from 7.68 to 8.24. Colour and appearance score goes on increasing upto the sample S₂, after that it was decreased.

 
Flavour
 
Data presented in Table 2 indicated that flavour score were 8.35, 8.48, 8.56, 8.13 and 7.73 for burfi prepared under T₁, T₂, T₃, T₄ and T₅ treatments respectively. This showed that as the level of black gram flour increases the flavour score of burfi also increases to 5%, but in T₄ and T₅ treatments the flavour score decreases. For flavour characteristic, burfi prepared under different treatments differ significantly. The highest score of flavour was for T₃ (8.56) with 5 per cent black gram flour due to acceptable amount of added black gram flour gives typical flavour while the lowest score was for T₅ (7.73) treatment with 10 per cent of black gram flour having deep beany flavor to burfi.
 

       
These results were found to be in close agreement with Jadhav (2015). For specified treatments it was observed as 7.01, 7.36, 7.63, 6.93 and 6.00 respectively. This showed that there was instant reduction of score with an increasing level of besan. Yadav and Peter (2015) observed that burfi prepared from the blend of whole milk and soymilk increased upto desired limit for flavour score ranged from 8.14, 8.26, 8.50 and 8.28. It showed that further decrease from treatment T₃. Kamble et al., (2019) reported that flavour score of green chickpea burfi ranged from 7.25 to 8.00. Score increased upto treatment T₃, but for treatment T₅ it decreased and get score of 7.25.
 
Body and texture
 
From Table 3 it was observed that body and texture score for treatments T₁, T₂, T₃, T₄ and T₅ were 8.25, 8.38, 8.46, 8.03 and 7.63 respectively. The highest body and texture score was obtained for the burfi blended with 5% black gram flour. Then after the level of black gram flour increases the body and texture score was decreases.
 

       
Kapare (2017) reported that the level of finger millet increases the body and texture scores also decreases and reported the average body and score ranges between 7.30 to 8.93. Kamble et al., (2019) reported that body and texture score decreased with increased in green chickpea level from 8.18 to 7.00.
 
Overall acceptability
 
From the Table 4 it is seen that overall acceptability score were 8.27, 8.38, 8.51, 8.03 and 7.64 under the treatments T₁, T₂, T₃, T₄ and T₅ respectively. Since the overall acceptability score of all the samples were above 5.5, it was defined that black gram burfi which prepared under all treatments were acceptable. Total sensory score of black gram burfi differed significantly due to the different levels of flour added. Treatment T₃ (8.51) was highly acceptable over T₁ (8.27), T₂ (8.38), T₄ (8.03) and T₅ (7.64). Among all the samples, T₃ sample has good flavour, body and texture with no deleterious effect on colour and appearance. It was having significant natural flavour of black gram and slightly smooth to granular texture. Therefore, it was liked by all judges among all the treatments including control sample.
 

       
The results of present investigation are more or less similar with findings of Jadhav (2015) recorded the overall acceptability score 7.07, 7.17, 7.70, 6.78 and 6.14 for treatments T₀ to T₄. Total sensory score of besan burfi differed significantly due to besan level used. It had superior body, smooth texture with no deleterious effects on colour and appearance.
 
Shelf life of black gram burfi
 
Storage study was conducted to know the shelf life of product at room (30±2^oC) temperature and refrigerated (7±2^oC) temperature. The sample was evaluated for organoleptic changes at 3 days interval upto 12 days at room temperature and upto 21 days at refrigerated temperature. Sensory evaluation of burfi was carried out by panel of judges in respect of colour and appearance, flavour, body and texture and overall acceptability.
 
Effect on sensory parameters of black gram burfi samples
 
From the Table 5, it was observed that, Sensory scores of standardized T₃ burfi sample which stored at room (30±2^oC) temperature conditions in terms of colour and appearance, flavour, body and texture and overall acceptability were observed in the range of 8.60-5.00, 8.70-4.80, 8.70-5.00 and 8.67-4.93 and at refrigerated (7±2^oC) temperature it was 8.60-5.65, 8.50-5.60, 8.50-6.10 and 8.53-5.78 respectively. The consecutive changes in overall acceptability score were non-significant upto 6 days after that it was decreased to 4.93 (p≤0.05). This indicated that product was no more acceptable for consumption. This was attributed to characteristic colour changes from creamy white to dark, change in flavour and hardness due to the loss of moisture and rancidity occurred in the samples which stored at room temperature. Whereas, in refrigerated condition overall acceptability score changes non-significant upto 9 days thereafter, change was found to be significant. The score above 6 shows that burfi samples were acceptable and consumable.
 

 
Effect on microbial attributes of black gram burfi samples
 
From the Table 6, it was observed that, the SPC and YMC counts represents collective enumeration of the overall microbial quality of burfi, just after preparation and during storage period. The absence of coliform count was detected throughout storage period at both room (30±2^oC) temperature and refrigerated (7±2^oC) temperature. During the storage period, SPC and YMC counts increased significantly (p≤0.05). At the end of 9^th day, fungal growth was clearly observed on burfi surface. The SPC and YMC values of burfi samples at 9^th day were 4.34 and 2.36 log cfu/g respectively. Therefore, further microbial study was discontinued and concluded that product stored at room temperature was unsafe for consumption. At refrigerated storage temperature, the rate of increase in SPC and YMC counts was low. It was ranges from 2.38 to 4.57 and 0 to 2.01 log cfu/g for SPC and YMC at 21 days respectively.
 

       
Sharma et al., (2017) reported shelf life of standardized kajukatli. It contained SPC and YMC count as 4.35 and 2.38 log cfu/g at room temperature (30±2^oC) for 0 to 12 days and 2.42 to 4.32 log cfu/g for SPC and 0 to 1.82 log cfu/g for YMC at refrigerated (7±2^oC) temperature for 0 to 30 days.
 
Cost of preparation of black gram flour burfi
 
From the Table 7, it was observed that, the production cost of burfi prepared using different levels of black gram flour was minimum as compared to that of controlled burfi. The cost of production of burfi with black gram powder was Rs. 255.38, Rs. 252.45, Rs. 249.62, Rs. 246.90 and Rs. 244.28 per kg for treatment T₁, T₂, T₃, T₄ and T₅ respectively. Above results showed that cost of 1 kg burfi for treatment T₁ (control sample i.e., prepared entirely from buffalo milk) was highest (Rs. 255.38). While the cost was noted for treatment T₅ (with 10% black gram flour) was lowest (Rs. 244.28). It was noticed that cost of product decreased from Rs. 255.38 to Rs. 244.28 with increased in the incorporation of black gram powder. It was further noticed that production cost of udid dal burfi goes on decreasing simultaneously at 2.5, 5, 7.5 and 10 per cent level of black gram flour because of higher recovery and low cost of black gram as compared to controlled burfi. On the basis of sensory evaluation, the cost of most acceptable burfi (T₃) was found Rs. 249.62.
 

       
Similar findings are found by Jadhav (2015) in besan burfi as production cost goes on decreasing with added level of besan i.e., Rs. 221.80, Rs. 216.30, Rs. 215.00, Rs. 214.10 and Rs. 213.10 per kg for treatment T₀, T₁, T₂, T₃ and T₄ respectively. Yadav and Peter (2015) showed in burfi prepared from whole milk with soymilk that for treatments T₀, T₁, T₂ and T₃ the production cost was Rs. 163.20, Rs. 152.32, Rs. 141.4 and Rs. 130.26 per kg. Kale (2018) reported similar results in sesamum powder burfi having cost of production was Rs. 350.33, Rs. 343.14, Rs. 326.26 and Rs. 321.22 per kg under treatments T₀, T₁, T₂ and T₃.

On the basis of sensory evaluation, the burfi prepared from 95% khoa and 5% black gram flour (T₃) was found highly acceptable over other treatments in respect to colour and appearance, flavour, body and texture and overall acceptability. Storage study was conducted at room (30±2^oC) temperature and refrigerated (7±2^oC) temperature conditions. The cost of more acceptable burfi prepared from incorporation of 5% black gram flour was Rs. 249.62 per kg.

This research would not have been possible without the support of many people.  I would like to express my deepest sense of gratitude and high indebtedness towards my dedicated, enthusiastic honourable guide Dr. S.G. Narwade, Associate Professor, College of Agriculture, VNMKV, Parbhani for his noble advice, constructive criticism, sustained interest and constant encouragement till the final shaping of present investigation. I am sincerely thankful to the advisory committee members Dr. G.K. Londhe, Professor and Head (COA), Dr. R.A. Patil, Assistant Professor (COA) and Dr. D.S. Chavan, Senior Scientist, Cattle Cross Breeding Project, Department of Animal Husbandry and Dairy Science, Vasantrao Naik Marathwada Krishi Vidyapeeth, Parbhani for their co-operation and valuable suggestion during research work.

None.