Instant rice products with good quality, inhibited starch retrogradation and enhanced storage stability, process of making the same by a two-stage enzymatic hydrolysis technique, and use thereof

Abstract

This invention relates to a method for manufacturing a long-term stored ready-to-eat rice product, comprising a two-stage enzymatic hydrolysis technique using maltose amylase. First, washed raw rice is soaked in an aqueous solution containing maltose amylase to obtain rice material that has undergone a first-stage enzymatic treatment. Next, the first-stage enzymatically treated rice material is mixed with other ingredients to obtain a composite material. The composite material is then mixed with the aqueous solution containing maltose amylase and cooked to obtain a second-stage enzymatically treated semi-finished product. Finally, the product is heat-treated at high temperature to obtain the ready-to-eat rice product. The ready-to-eat rice product produced by this invention, through a two-stage enzymatic hydrolysis technique, modifies the starch structure in the rice grains, not only improving the texture of the ready-to-eat rice product but also effectively inhibiting starch retrogradation and enhancing storage stability, thus possessing broad application prospects.

Claims

1. A method for manufacturing an instant rice product, comprising the following steps: (1) a first-stage enzyme hydrolysis step, comprising soaking raw rice in a first aqueous solution containing an enzyme for 30 to 50 minutes at a temperature of room temperature to 30°C, wherein the enzyme contains maltose amylase; (2) draining the water to obtain rice material that has undergone one-time enzyme treatment; (3) optionally combining the rice material that has undergone one-time enzyme treatment with ingredients to obtain a composite material; (4) adding a second aqueous solution containing an enzyme to the rice material that has undergone one-time enzyme treatment obtained in step (2), or to the composite material obtained in step (3), wherein the enzyme contains maltose amylase; (5) a second-stage enzyme hydrolysis step, comprising cooking at a temperature of 85°C to 95°C for 45 to 55 minutes to obtain a semi-finished rice product; and (6) subjecting the semi-finished rice product to high-temperature treatment at at least 120°C to obtain an instant rice product.

2. The method of claim 1, wherein the enzyme added in steps (1) and (4) is composed of maltose amylase.

3. The method of claim 1, wherein the amount of enzyme added in step (1) is 0.04% to 0.10% by weight of the total weight of raw rice.

4. The method of claim 1, wherein the raw rice used in step (1) includes different varieties of rice.

5. The method of claim 1, wherein the raw rice used in step (1) includes rice obtained by different processing methods or pretreatment.

6. The method of claim 1, wherein the ingredients used in step (3) include one or more other grains, meats, plants or their products.

7. The method of claim 1, wherein step (4) comprises adding an aqueous solution containing enzymes and the rice material obtained in step (2) after one enzyme treatment or the combination material obtained in step (3) to a heat-resistant filling container.

8. The method of claim 1, wherein the amount of enzyme added in step (4) is 0.08% to 0.15% by weight of the total weight of the aqueous solution containing the enzyme.

9. The method of claim 1, wherein step (5) further comprises a degassing process.

10. The method of claim 1, wherein the high-temperature heat treatment in step (6) is performed at a temperature of 120°C to 130°C for a time of at least 58 minutes.

11. An instant rice product made by any one of the methods claimed in claims 1 to 10.

12. The ready-to-eat rice products in claim 11 are canned ready-to-eat rice products.