JP7668500B2 - Pulp containing tea seed oil extraction residue and pulp product produced from said pulp, and method for producing pulp containing tea seed oil extraction residue - Google Patents

Description

The present invention relates to pulp to which tea seed oil expression residue has been added, a pulp product produced from said pulp, and a method for producing pulp to which tea seed oil expression residue has been added. More specifically, the present invention relates to pulp that has antioxidant properties by utilizing the antioxidant components contained in tea seed oil expression residue, a pulp product produced from said pulp, and a method for producing pulp to which tea seed oil expression residue has been added.

In recent years, tea seed oil has been attracting attention as a healthy oil, as it is known to be rich in oleic acid, like olive oil, and to have a low content of saturated fatty acids. This tea seed oil is produced by extracting the seed embryo from the tea seed and squeezing the oil components contained in the seed embryo (see, for example, Patent Document 1).

Furthermore, in recent years, the demand for tea-based beverages has grown due to the growing consumer preference for healthful drinks, and this has led to an increase in the amount of hydrated tea leaves discarded. For this reason, it has been proposed to reuse tea leaves by wet-grinding them and adding them to raw pulp, while also producing raw pulp with antibacterial and deodorizing properties (see, for example, Patent Document 2).

Disposable tableware and lunch boxes made from raw pulp are preferable because they place less of a burden on the environment when disposed of compared to tableware and lunch boxes made from petroleum. On the other hand, measures have been taken to prevent food deterioration, such as by including sheets impregnated with antioxidant compounds or sinigrin, the spicy component of wasabi, in lunch boxes and the like (see, for example, Patent Document 3).

JP 2020-152749 A JP 2008-255515 A Japanese Patent Application Publication No. 3-222574

Patent Document 2 proposes using tea leaves generated during tea extraction to add to raw pulp to produce pulp with antibacterial and deodorizing properties, but the inventors discovered that the tea seed oil extraction residue (pomace) generated in the process of producing tea seed oil, as in Patent Document 1, contains a large amount of antioxidant substances.

In addition, as in Patent Document 3, it has been proposed to include sheets impregnated with antioxidant compounds or sinigrin in order to prevent food deterioration, but there have been no pulp products such as tableware or lunch boxes that have antioxidant properties in themselves.

Therefore, the present invention aims to provide pulp and pulp products with antioxidant properties by adding tea seed oil extraction residue to raw pulp.

To achieve the above object, the pulp containing tea seed oil expression residue of the present invention is characterized in that the tea seed oil expression residue discharged when the seed embryo of the tea seed is pressed is processed into a powder to form a tea seed oil expression residue powder, the powder is added to the raw pulp, water is added to form a pulp slurry, the pulp slurry is prepared, paper is made, and the pulp slurry is dehydrated to form the pulp.

The pulp product of the present invention is characterized in that it is produced from pulp to which the tea seed oil extraction residue has been added, and it is preferable that the pulp product is tableware.

Furthermore, the method for producing pulp to which tea seed oil expression residue has been added of the present invention is characterized by sequentially carrying out the steps of processing the tea seed oil expression residue discharged when the seed embryo of tea seeds is pressed into a powder form to form a tea seed oil expression residue powder, adding the powder to raw pulp and then absorbing moisture to form a pulp slurry, preparing the pulp slurry and making paper, and dehydrating the paper-made pulp.

Pulp made from the residue of tea seed oil extraction according to the present invention can produce pulp with antioxidant properties. In addition, tea seed oil has been used as an effective way to utilize tea seeds that were originally harvested by hand, but the residue left after oil extraction can also be effectively utilized, which is thought to lead to environmental conservation on land and the elimination of unpaid (low-wage) labor by agricultural workers.

In addition, by using this pulp to manufacture pulp containers such as plates, trays, and lunch boxes (the pulp products of the present invention), it is possible to delay the oxidation and decay of foods such as vegetables, fruits, fish, meat, and eggs stored in these containers. Furthermore, by using this pulp to manufacture pulp tableware such as straws, spoons, forks, knives, chopsticks, and stirrers (the pulp products of the present invention), it is possible to provide tableware with antioxidant properties.

1 is a flow chart showing the first step of producing pulp containing tea seed oil extraction residue of the present invention. 3 is a flow chart showing the second step of producing pulp containing tea seed oil extraction residue of the present invention. 1 is a graph comparing the magnitude of antioxidant effects of plates made using pulp containing tea seed oil extraction residue.

Figures 1 and 2 show the process for producing pulp containing tea seed oil residue of the present invention. First, based on Figure 1, we will explain the first step of processing the tea seed oil residue to be added to the raw pulp into powder.

In the first step, the seed embryo extraction step S1 is carried out to remove the outer skin from the harvested tea seeds and extract the seed embryos containing the tea seed oil. The extracted seed embryos are then dried, crushed and compressed to extract the tea seed oil in the pressing step S2. The pressed tea seed oil is then extracted in the tea seed oil extraction step S3. After the tea seed oil is extracted, the residue extraction step S4 is carried out to extract the block-shaped residue. The residue crushing step S5 is carried out to crush the block-shaped residue. The crushed residue is then sieved in the residue sieving step S6. These steps are carried out in sequence to obtain a powder of tea seed oil expression residue (hereinafter referred to as powdered residue).

In the residue crushing step S5, the block-shaped residue (approximately 1 kg to 4 kg per piece) is crushed to approximately 40 mm, and then further crushed to 2 mm. In the residue sieving step S6, powdered residue of 1 mm to 10 mm is collected (seed embryo removal step S1 to residue sieving step S6 are steps for forming the powdered residue of the present invention).

Next, based on FIG. 2, we will explain the second step of adding the powdery residue obtained in the first step to the raw pulp to produce the pulp of the present invention.

In the second step, the following steps are carried out in sequence: an addition step S7 in which powdered residue is added to the raw pulp; a pulper step S8 in which the pulp to which the powdered residue has been added is moistened (swelled) and then cut into long and short fibers to make the fibers more flexible (the addition step S7 and the pulper step S8 are steps of forming a pulp slurry in the present invention); a beating step S9 in which the pulp slurry after the pulper step is beaten (cut and crushed) to fluff the fibers (fibrillate) and promote bonding; a papermaking step S10 in which the pulp slurry is evenly sent over a wire (plastic net) to make paper (the beating step S9 and the papermaking step S10 are steps of preparing the pulp slurry of the present invention and making paper); and a dewatering step S11 in which the pulp slurry is dried through a press part and a dryer part (the dewatering step S11 is a step of dewatering the paper-made pulp of the present invention). This produces a pulp to which powdered residue has been added.

The types of raw materials used for the raw pulp include wood raw materials made from conifers and broad-leaved trees, and non-wood raw materials made from kapok fruit, bamboo, Manila hemp, kenaf, etc., and the ratio of tea seed oil expression residue powder added in the addition process S7 is 90-50% raw material and 10-50% tea seed oil expression residue powder. When coloring the pulp, the beating process S9 is followed by the dyeing process S12, and the papermaking process S10 is carried out after the dyeing process S12 is completed.

The pulp produced through the first and second steps is processed through well-known processes into various pulp products such as plates, trays, lunch boxes, straws, spoons, forks, knives, chopsticks, stirrers, etc.

The pulp produced as described above contains antioxidants derived from the residue of tea seed oil extraction, so by using this pulp to produce pulp containers such as plates, trays, and lunch boxes, it is possible to delay the oxidation and decay of foods such as vegetables, fruits, fish, meat, and eggs contained in these containers. Furthermore, even if this pulp is used to produce tableware other than pulp containers, such as straws, spoons, forks, knives, chopsticks, and stirrers, products with antioxidant properties can be provided.

Next, as shown in Figure 3 and Table 1, the pulp produced as described above was used to form plates B and C by thermoforming using a metal mold, and the antioxidant activity of plates B and C was measured and compared using the standard Trolox Equivalent Antioxidant Capacity (TEAC) method (hereinafter referred to as the "TEAC method").

Plate B was made by adding 10 w/w% powdered residue to the raw pulp, and plate C was made by adding 30 w/w% powdered residue to the raw pulp, and the TEAC method was used to examine the extent to which the antioxidant effect was maintained compared to the powdered residue (raw powder). In addition, the TEAC method was also used to examine the extent to which the antioxidant effect was maintained for the normal plate A (blank), which was made only from raw pulp without adding powdered residue, and this was used for comparison. (The samples described below refer to the powdered raw materials of plates A to C.)

For the specimens of plates A-C and powdered residue, 4 mL of a mixture of 0.2 v/v% aqueous acetic acid and methanol (75:25) was added to 400 mg of cut dried samples of plates A-C and powdered residue, and the mixture was extracted with ultrasound for 10 minutes, then conditioned by passing through a 0.45 μm membrane filter. The magnitude of the antioxidant effect of each specimen was compared by comparing the Trolox equivalent (μmol/L) of each specimen measured by the TEAC method.

As shown in Figure 3 and Table 1, the Trolox equivalent of the sample in plate B was 176.5 μmol/L, and the Trolox equivalent of the sample in plate C was 255.8 μmol/L. These correspond to 8.7% for the sample in plate B and 12.9% for the sample in plate C, relative to the powdered residue (raw powder). Although these antioxidant effects are reduced relative to the amount of powdered residue added to the raw pulp, they indicate that more than 40% of the antioxidant effect remains even after heat treatment such as thermoforming in a mold. On the other hand, in blank plate A, the Trolox equivalent was 0.55 μmol/L, and almost no antioxidant effect was observed, confirming that adding powdered residue can impart antioxidant function to paper plates.

Furthermore, when the strength of plates B and C was checked, it was confirmed that they had sufficient strength. Therefore, they have sufficient strength and are practical for use in producing various pulp products such as not only plates, but also tableware such as trays, lunch containers, straws, spoons, forks, knives, chopsticks, stirrers, etc. Furthermore, while conventional pulp products become fuzzy or peel off into powdery particles due to fibrillation with use, it was confirmed that the surfaces of plates B and C mentioned above remain smooth even with repeated use and are less likely to fibrillate.

S1... Seed embryo extraction process, S2... Squeezing process, S3... Tea seed oil extraction process, S4... Residue extraction process, S5... Residue crushing process, S6... Residue sieving process, S7... Addition process, S8... Pulper process, S9... Beating process, S10... Paper making process, S11... Dehydration process, S12... Dyeing process

Claims (4)

A pulp containing tea seed oil expression residue added thereto, which is formed by processing tea seed oil expression residue discharged when oil is expressed from tea seed embryos into a powder form to form a powder of tea seed oil expression residue, adding the powder to raw pulp, and then allowing water to be absorbed to form a pulp slurry, preparing the pulp slurry, making paper from the paper, and then dehydrating the paper. A pulp product produced from pulp containing the tea seed oil extraction residue according to claim 1. The pulp product according to claim 2, characterized in that the pulp product is tableware. A step of processing tea seed oil expression residue discharged when oil is expressed from tea seed embryos into a powder form to form a tea seed oil expression residue powder;
adding the powder to a raw pulp and then absorbing moisture to form a pulp slurry;
preparing the pulp slurry and making paper;
A method for producing pulp containing added tea seed oil expression residue, comprising the steps of:

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