JPH01256350A - Food using silk fibroin and production thereof - Google Patents

Abstract

PURPOSE:To produce a food being extremely soft and pleasant to the palate, by adding drink to an aqueous solution of silk fibroin and gelling the fibroin. CONSTITUTION:A silk thread or waste cocom, waste silk thread, etc., is used as a fibroin source and sericin is dissolved and removed according to a conventional method to provide an aqueous solution of silk fibroin. Drink such as juice, soup, nutritional drink, etc., is added to the above-mentioned aqueous solution and preferably pH of the mixture is adjusted to nearly pH 4 which is isoelectric point to gell the fibroin.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a food product using silk fibroin that has an extremely smooth texture.

<Prior Art> Various gelled foods such as pudding and jelly have been known, but gelled foods using fibroin, which constitutes silk, have not yet been known.

<Problems to be Solved by the Invention> The present inventor has been conducting extensive research on silk, and has now succeeded in developing a gelled food using fibroin, which constitutes silk.

That is, an object of the present invention is to provide a food product using silk fibroin that has an extremely smooth texture called silky touch.

Means for Solving the Problems> According to a first aspect of the present invention, the present invention is characterized by comprising a porous body of silk fibroin and a beverage contained in the porous body, and exhibiting a gel-like state. Foods using silk fibroin are provided.

According to a second aspect of the present invention, there is provided a method for producing a food using silk fibroin, which comprises adding a beverage to an aqueous silk fibroin solution and gelling the fibroin.

The present invention will be explained in more detail below.

The present invention relates to the application of a previously unknown composition to foods. Silk thread is a fibrous protein expelled by silkworms, and consists of two fibroin fibers bound together by sericin.

Of these, the present invention utilizes fibroin fibers, which have conventionally been obtained by dissolving and removing sericin through milling. Fibroin is a protein containing extremely high amounts of glycine (Gly) and alanine (Ala), (G 1 y 3A 1 a 2X
2), (X is an amino acid other than Gly or Ala).

In the present invention, this aqueous solution of fibroin is used.

To obtain a fibroin aqueous solution, for example, silk threads are first immersed in a 0.5% solution of Na2Co, boiled water, etc. to remove sericin, obtain fibroin fibers, and then soaked in a LiBr saturated aqueous solution, CaC112, Ca C
It dissolves easily when placed in a solution containing a neutral salt such as fl 2 □ + EtOH. When this solution is dialyzed and desalted, a clear regenerated fibroin solution is obtained.

If this aqueous fibroin solution is freeze-dried and powdered, silk powder can be obtained, if it is cast, a film can be obtained, and if it is gelled, a pudding-like substance can be obtained.
Furthermore, when fibroin is gelled, that is, crosslinked, it assumes a β structure, becomes a three-dimensional network structure, and forms a porous body.

The present invention provides a gelled silk fibroin food product by incorporating a beverage into a porous body obtained by gelling silk fibroin.

Here, the term "beverage" is not particularly limited, and refers to liquid foods such as palatability drinks such as juices, soups, and nutritional drinks.
It may contain solid content. Furthermore, it goes without saying that gelled foods using silk fibroin may contain additives that are generally added to foods, such as sweeteners, colorants, flavoring agents, and fillers.

Foods using such silk fibroin can be produced by the method described below.

First, a fibroin aqueous solution is prepared by the method described above. Since it is used for food, it is preferable to use a neutral salt that is not harmful to the human body, such as CaCl2, EtOH, or a mixture thereof.

Next, the above-mentioned beverage is added to the fibroin aqueous solution, mixed well, and then gelled. If the fibroin aqueous solution has a concentration of about 1% or more, it will gel even if left standing.
However, in order to increase the yield in a short time, it is preferable to promote gelation, and methods such as pH adjustment, addition of sericin, and heating to an extent that does not denature the fibroin can be used.

When performing gelation by adjusting the pH, it is better to set it to the acidic side rather than the alkaline side, and in particular, gelation can be quickly achieved by adjusting the pH to near Nakamura, which is the isoelectric point of fibroin. For example, it is preferable to use an organic acid such as citric acid to adjust the pH.

When the aqueous fibroin solution containing the beverage is gelled in this manner, the beverage is included in the cavities of the porous body with a three-dimensional network structure formed by cross-linking the fibroin, resulting in a gel-like food product. As mentioned above, food additives etc. may be added to this in advance.

The hardness of the obtained gelled food containing the silk fibroin beverage can be adjusted depending on the concentration of fibroin.

The gelled food containing this silk fibroin beverage has a wonderfully smooth texture that can be called a silky touch.

Note that as the fibroin source used to obtain the fibroin aqueous solution, inexpensive sources such as kudzu cocoon and kudzu silk thread can be used, and therefore gelled silk fibroin foods can also be produced at low cost.

<Example> Hereinafter, the present invention will be specifically explained with reference to examples.

(Example) A fibroin aqueous solution was prepared using waste threads and waste cocoons as raw materials and was refined according to a conventional method. The test was carried out twice for 30 minutes at a liquid temperature of 90° C. (in a hot bath) using a 0.5% sodium carbonate solution in an amount 50 times the amount of the bath. Next, fibroin was dissolved in a mixed aqueous solution of calcium chloride and ethanol, filtered under suction, poured into a cellulose tube, and dialyzed in pure water until no Ca ions were observed to prepare an aqueous fibroin solution with a concentration of 4%.

Commercially available 100% orange juice was added to this fibroin aqueous solution, and the pH was adjusted to about 4 using citric acid.
Foods were obtained by gelatinizing silk fibroin.

This gelled silk fibroin food had a smooth texture that was between commercially available pudding and jelly.

<Effects of the Invention> The food obtained by gelling silk fibroin containing the beverage provided by the present invention has a smooth and wonderful texture.

Foods using this silk fibroin can be easily produced by simply adding a beverage to an aqueous solution of fibroin and allowing it to gel.

Furthermore, since the aqueous fibroin solution can be easily prepared at low cost and in large quantities from inexpensive materials such as kudzu cocoon, food products can be produced inexpensively and in large quantities using silk fibroin.

Claims (3)

[Claims] (1) A food using silk fibroin, which is characterized in that it contains a porous body of silk fibroin and a beverage contained in the porous body, and has a gel-like appearance. (2) A method for producing a food using silk fibroin, which comprises adding a beverage to an aqueous silk fibroin solution to gel the fibroin. (3) The method for producing a food product using silk fibroin according to claim 2, wherein the gelation of silk fibroin is performed by adjusting pH.