Soybean milk is usually produced in its natural flavor. Consequently, its appeal to consumers is limited. A technique to add flavor, especially fruit flavors, has been devised to provide greater varieties of soybean milk, and more nutritional value for consumers.
The goal is to attract additional young and aged people to drink more soybean milk which has high protein, vitamin C, calcium, and a healthy substance known as isoflavone, which acts like estrogen hormones that reduce the risk of cancer, heart disease and calcium-deficiency in aged women following menopause.
Generally, soybean milk has a natural beany flavor, which is not popular among some consumers. Milk manufacturers have therefore started to add various flavors by blending it with passion fruit, guava (Fig. 1), or lime juice. Soybean milk (Fig. 2) is high in protein, and tends to become silted when acid fruit juice is blended.
The silting depends on the level of acidity in each type of fruit. Usually, the protein in soybean milk will silt at pH 4.5 (isoelectric point). If blended with fruit juice, it becomes more silty. However, a proteolytic enzyme can be employed to slow down the silting and stabilize the protein.
How to Produce Flavored Soybean Milk
- Wash 130 g of beans 3-4 times in water.
- Steam the beans at 60-80 °C for 3 hours.
- Grind the beans in 1,300 mg of boiled water (80-100 °C) in a blender for 10-15 minutes. Filter the soybean milk with a filter cloth.
- Boil 1 liter of soy bean milk. After boiling, reduce the temperature and continue to simmer for about 5 minutes.
- Add 9 percent sugar and 0.3 percent pectin by weight to the volume of soybean milk.
- Add 0.3 percent enzyme alkales by dry weight of beans at 50 °C and stir it for about 10 minutes.
- Boil it for another 5 minutes. Soybean milk at 85 °C is ready to be blended with fruit juice/paste.
- Wash the passion fruit in clean water and cut it into two parts.
- Scoop out the flesh with a spoon and filter it with a filter cloth.
- Heat the passion fruit paste (Fig. 3) to 85 °C for 10 minutes
- Wash guava in clean water and cut it into small pieces. Remove the seeds.
- Stir 1 kg of guava flesh in 250 ml of warm water and filter it with a filter cloth.
- Heat the guava paste to 85 °C for 10 minutes.
- Wash lime in clean water and cut into two parts. Extract the juice with a squeezer.
- Filter it with a filter cloth.
- Heat the lime juice to 85 °C for 10 minutes.
Fruit-Flavored Soybean Milk
Blend the soybean milk with the fruit juice at 85 °C in a ratio of
- 80:20 soybean milk: passion fruit juice
- 70:30 soybean milk: guava juice
- 95:5 soybean milk: lime juice
- Fill 2 liters of fruit-flavored soybean milk at 85 °C into 250-ml plastic bottles, sterilized at 85 °C.
- Seal and turn the bottles upside down and store them at 10 °C temperature.
- The fruit-flavored soybean milk (Fig. 4) can be kept for 2 weeks.