Development , Organoleptic Evaluation and Acceptability of Products Developed from Agro Based Wastes-Seeds and Rind of Watermelon

Abstract The aim of the present study was to utilize, develop and evaluate value added products of agro based waste-seeds and rind of watermelon. In view of its high nutritional content, they have very good potential food value to serve as supplements in food formulations. Four products were developed (Juice, Salad, Jam and Protein bars) along with their respective variations, from which Juice and Salad were subjected only for numerical scoring whereas Jam and Protein bars were subjected to detailed hedonic scaling. Protein bars containing ragi flakes and jam made only with Watermelon rind were the most acceptable amongst the three and two respective formulations. Statistical analysis was applied and fudicial limits of the above mentioned parameters were obtained.


Introduction
The most common problems in food processing is the disposal of the sub-products generated.This "waste material" produces ecological problems related to the proliferation of insects and rodents and an economic burden because of transportation to repositories.Therefore strategies for the profitable use of this material are needed.In recent times more attention has been focused to recover valuable components from neglected food parts (food "losses", "wastes", "by-products" or "wasted by-products") and recycle them inside the food chain, in an economic and sustainable way.The juice or pulp from watermelon is considered as the edible portion but rind and seeds are discarded as major solid wastes [1][2].Watermelon seeds are known to be highly nutritional; they are rich sources of protein, B vitamins, minerals (such as magnesium, potassium, phosphorous, sodium, iron, zinc, manganese and copper) and fat among others as well as phytochemicals.The seeds of watermelons are known to have economic benefits especially in countries where cultivation is on the increase.Watermelon rind contains citrulline, a non-essential amino acid, which converts to L-arginine when eaten.

Procurement of the raw material
The raw materials required for the preparation of the products were procured from a supermarket named Ratnadeep at Tolichowki, Hyderabad.Watermelon and watermelon seeds were procured from a local market from Mehdipatnam, Hyderabad.

Standardization of the recipe
Standardization is the process where a recipe is tested number of times and found a satisfactory in quantity and yield.It is a gradual trial process.The standardization procedure was carried out by repeated trials till an acceptable recipe for the preparation of the product was obtained.The amounts were finalized by assessing the appearance, texture and taste of the variations.The finalized products were jam, juice, salad and protein bar.Amounts of all the ingredients in the formulation of different products:  Peel the outer covering of watermelon and cut the rind into small pieces.
Add enough water and pressure cook the rind with a small piece of cinnamon for about 5 whistles.
Remove the cinnamon and grind the rind to a pulp to obtain a uniform mass.
Measure the pulp, add sugar according to the sweetness required.
Cook the mixture slowly with constant stirring till the mixture is reduced to half.
Add watermelon seeds, lemon juice and essence.
Test the sample of cooked mixture for jam.
When it is done, remove from fire, pour into a sterilized bottle kept on a wooden platform and seal it tightly.Peel the outer covering of watermelon and cut the rind into small pieces.

J Food Sci Nutr
Add enough water and pressure cook the rind for about 5 whistles.
Remove the peel of apple; grind the rind and apple to a pulp to obtain a uniform mass.
Measure the pulp, add sugar according to the sweetness required.
Cook the mixture slowly with constant stirring till the mixture is reduced to half.
Add watermelon seeds, color and essence.
Test the sample of cooked mixture for jam consistency.
When it is done, remove from fire, pour into a sterilized bottle kept on a wooden platform and seal it tightly.Note: The method of preparation for variation 2 and variation 3 is same as variation 1 besides adding cumin powder and mint juice.

Salad Variation 1 (Pineapple)
Figure 4: Flow diagram for preparation of watermelon rind salad incorporated with pineapple.
Note: The method of preparation for variation 2 and variation 3 is same as variation 1 besides adding strawberry and papaya.
Peel the outer covering of watermelon and cut the rind into small pieces.
Grind the rind and sieve it through a strainer.
Add powdered watermelon seeds and lemon juice.
The juice is ready to serve.
Peel the outer covering of watermelon and grate the rind.
Add curd, cream, mustard powder, sugar, salt, powdered watermelon seeds, pineapple pieces and mix well.Note: The method of preparation for variation 2 and variation 3 is same as variation 1 besides adding jowar flakes and ragi flakes.

Sensory evaluation of the developed products
The sensory evaluation of the five developed samples (Jam-2; Protein bar-3) was carried out by 70 semi-trained panelists.The panelists made hedonic evaluation of the samples and were asked to assess the jam and protein bars for overall acceptability based on the color, taste and texture.

Statistical analysis of nutrient content of the products
Moisture Analysis was followed by Ashing.After dry ashing is done, incineration at high temperature (525˚C or higher) accomplished in a muffle furnace.Estimation of mineral content such as and Iron (Fe), Calcium (Ca) were performed using titrimetric method.The iron content in protein bar with bajra flakes (Variation 3) is the highest (0.92 mg/100 g) and least is Variation 1 with ragi flakes (0.61 mg/100 g).The calcium content in protein bar with ragi flakes (Variation 1) is the highest (88.3 mg/100 g) and least is Variation 2 with jowar flakes (0.61 mg/100 g).
Peel the outer covering of watermelon, dry the rind.
Grind the rind, ragi flakes and dates separately.
Mix together powdered watermelon seeds, powdered rind, powdered ragi flakes and dates to form a bar.
Keep the bar in the refrigerator for one hour so that it becomes firm.
The protein bar is ready to serve.

Figure 2 :
Figure 2: Flow diagram for preparation of Watermelon rind jam with apple.

Figure 3 :
Figure 3: Flow diagram for preparation of watermelon rind juice incorporated with lemon.

Figure 5 :
Figure 5: Flow diagram for preparation of protein bars incorporated with ragi flakes.
J Food