Preparation of Squash

Principle

Fruit beverages are prepared from fruit juices or pulp and preserved by chemical preservatives or by heat application.

Requirements

Raw materials, equipment and apparatus

1. Fruit/vegetable, sugar
2. Peeler
3. Juicer
4. Pulper
5. Filter cloth / sieve
6. Pans of suitable size
7. Volumetric flask
8. Measuring cylinder
9. Weighing balanceChemicals and reagents

1. Hydrochloric acid

2. Citric acid / ascorbic acid

3. Potassium metabisulphite

4. Sodium benzoate

Ingredients

      Juice - 2.5 kg

            Sugar - 4.141 kg

            Citric acid - 100 g 4.25 Kg

            KMS - 9 g

            Water - (10-2.5+4.25) = 3.25 Lts

Theory

            Squash should contain at least 25% fruit juice or pulp and 40 to 50% total soluble solids commercially. About 1% citric acid and 350 ppm Sulphur dioxide or 600 ppm sodium benzoate are added as preservatives. By careful attention to hygienic condition the concentration of SO₂ in the squash can be safely reduced to about 250 ppm. Fruits most commonly used for preparing beverages are sweet orange, sour lime, mandarin (sangtra) loose jacket orange, mango, apple, grape fruit, pineapple, lemon etc.

Method of calculation

For the preparation of 10 liters of squash follow the procedure given below:

1. Calculate the amount of juice required as per commercial specification

      Required juice = (25/100) × 10 = 2.5 lts.

2. Measure the TSS using a refractometer (say the TSS is 30%)

            Calculate the total solids content of the juice i.e. 0.3 X 2.5 = 0.75 kg

3. The final required TSS content in the product is to be saying 50%. The TSS required to be added to obtain the final product is (0.5 × 10 – 0.75) kg = 4.25 kg

4. The amount of soluble solids in the form of citric acid and KMS is Citric acid @ 1%, in the final produce is 100 g i.e. 0.1 kg. 600 ppm SO2 (1.5g/litre of KMS being equivalent to 1000 ppm) @ 0.9g KMS/litre. i.e. 0.9 x 10 = 9 g i.e 0.009 kg.

5. Amount of solids to be added in the form of sugar is 4.25–(0.1+0.009)= 4.141 kg.

Preparation procedure

1.      As prescribe dissolve sugar in water, add citric acid and give a boil.

2.      Any dirt is strain through a fine muslin cloth.

3.      The syrup is cooled slightly.

4.      Extract juice from fresh fruits by crushing and pressing them by using suitable juice extractors, basket presses or fruit pulper. Fruits, which require preheating, should be preheated before extraction.

5.      Strain and filter the juice to remove suspended matter consisting of broken fruit tissue, seed, skin, etc. Clarify the juice if required using a suitable method.

6.      The clean syrup is blended with fruit juice.

7.      Add colour as required and then essence.

8.      To improve flavour peal emulsion of 2 to 4 oranges for every 100 oranges taken or an appropriate quantity of an essential oil is added to the squash.

9.       After mixing all the ingredients a calculated quantity of preservative, about 28 g for every 454 gram of squash is added.

10.  Now fill the squash into sterilized bottles, leaving about 1.2 to 2.5 cm of head space.

Observations

Determine TSS and acidity.

Result

Acidity of the given squash, cordial, nectar, RTS beverage = % (w/v)

TSS of the given squash, cordial, nectar, RTS beverage = %

Precautions

• All equipment used in the preparation of fruit juices and beverages should be rust and acid proof.
• Copper and iron vessels should be strictly avoided as these metals react with fruit acids, and cause blackening of the product.
• Avoid exposure of juice to atmosphere as it will spoil the colour, taste and aroma and also reduce the Vitamin content.