JPS63237768A - Preparation of turbid natural fruit juice of citrus fruits - Google Patents

Abstract

PURPOSE:To prepare a turbid natural fruit juice of citrus fruits, having strong and stable turbidity and preservable over a long period, by subjecting squeezed juice of citrus fruits to ultrafiltration and collecting non-permeated liquid as the objective turbid fruit juice. CONSTITUTION:Squeezed juice of citrus fruits is instantaneously sterilized at 85-95 deg.C for 20-50sec optionally after homogenization treatment. The sterilized juice is cooled and the produced flocculating coarse pulp particles are removed to obtain fruit juice. The fruit juice is subjected to ultrafiltration with an ultrafiltration membrane having a critical molecular weight of 20,000-80,000 and made of polysulfone, etc. The objective turbid fruit juice is obtained as non-permeated liquid and the permeated liquid is used as straight fruit juice or concentrated fruit juice.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention provides a method for producing natural cloudy fruit juice with a higher degree of cloudiness (and has excellent stability) than fruit juice obtained by squeezing citrus fruits. Regarding.

[Conventional technology]

Conventionally, brominated oils, fatty acid esters of sucrose, and the like have been used as clouding agents to impart a desirable cloudy state to fruit juice, but these synthetic clouding agents still have problems in terms of stability for the human body. The development of clouding agents and cloudy fruit juices using natural products as raw materials is progressing. Several proposals have been made in this regard. For example,
No. 11957 discloses that after squeezing the juice with a juice extractor, the juice lees (pulp) separated from the fruit juice are aqueous extracted using the juice extractor again, heated, and then applied to a Sharpless centrifuge. It has been proposed to produce a natural clouding agent by concentrating the extracted liquid.

In addition, Japanese Patent Publication No. 57-31 describes a method of grinding the natural fruit juice obtained after squeezing the juice as it is without separating the pulp, and removing the coagulated material from the fruit juice obtained at a temperature of 90°C or less. A method for producing naturally cloudy fruit juice by concentrating fruit juice has been proposed.

[Problem that the invention seeks to solve]

However, in the known methods for producing naturally cloudy fruit juice, the clouding power is weak, the dilution ratio is low, and problems remain in terms of storage stability, stability against changes in heat resistance, etc.

In addition, centrifugation, ordinary filter paper filtration, diatomaceous earth filtration, etc. can be considered as methods for separating and extracting natural turbid components.
Since the turbid component is mainly composed of polymeric colloidal substances, it is difficult to separate it by centrifugation, clogging occurs in ordinary filtration methods, and fractionation techniques at the molecular weight level are extremely difficult.

[Means for solving problems]

The present inventor has discovered that substances that cause turbidity (polymeric substances carotenoids, colloidal substances, etc.) that are present in natural fruit juices
We tried a fractionation technology using an ultrafiltration membrane that uses a molecular weight fractionation function to shut out the separation of low-molecular-weight substances that do not have a turbidity function. The present invention has been completed by discovering that by concentrating and separating the non-permeable components of the fruit juice, it is possible to obtain a thick natural cloudy fruit juice that is stable and can withstand long-term storage.

In the production method of the present invention, first, after squeezing citrus fruit, the fruit is directly thawed or stored frozen, and then subjected to treatments such as direct treatment, homogenization, grinding, etc., and instant sterilization treatment. The instant sterilization process deactivates pectin esterase activity, heat aggregation, and kills microorganisms. Sterilization conditions are temperature 85℃
〜95℃, time is 20 seconds to 50 seconds, preferably 90℃〜
A temperature of 93°C and 30 to 40 seconds is appropriate. Heating more than this is not preferable as it may cause quality deterioration such as browning. After cooling, the resulting solidified material is removed using a high-speed rotation centrifuge having a centrifugal effect of s,ooo to 10,0OOc. This is then subjected to ultrafiltration treatment. The module structure as an ultrafiltration device used in the present invention may be in any form of hollow fiber, tubular, wound, or flat membrane. The ultrafiltration membrane may be made of any commonly used material, but polysulfone membranes, cellulose membranes, polyfluorine membranes, etc. are preferred. Among them, polysulfone-based membranes, which are stable in chemical resistance and heat resistance, are desirable. The ultrafiltration membrane used has a molecular weight cut-off of 20,000 to so, ooo. As a result, polymeric substances, carotenoids, colloidal substances, etc. which cause turbidity are separated, and a turbid fruit juice is obtained which is mainly composed of particles of 5 microns or less and colloidal components of natural fruit juice. When using one having a molecular weight cut-off of less than 20,000, the filtration resistance becomes large and the operating cost becomes high, making it uneconomical. In addition, when using a fruit with a molecular weight cut-off of more than 80°000, some polymeric substances such as pectin will come out to the permeate side, resulting in a cloudy fruit juice obtained as a non-permeate liquid and a transparent fruit juice as described below obtained as a permeate liquid. The quality of both deteriorates, and both become unusable and uneconomical.

In the present invention, fruit juice with high turbidity can be obtained by separating soluble components and turbid components in naturally turbid fruit juice. The better the separation results between the two, the more the turbidity of the turbid area will increase. In addition, the liquid that permeates through the ultrafiltration process can be used as a transparent fruit juice as a straight fruit juice or concentrated fruit juice as a raw material for high-grade fruit juice drinks, fruit juice-containing gas drinks, lactic acid bacteria drinks, etc. The effect will further increase.

〔Example〕

Next, the present invention will be explained with reference to Examples and Test Examples.

Example 1 20 tons of Satsuma mandarin oranges were squeezed using an in-line juicer, and the diameter was 1
After removing coarse pulp with a ++n screen finisher, it was sterilized and cooled at 93°C with a plate heat exchanger, and then processed with a high-speed rotation centrifuge with a centrifugal effect of 9.0OOG to a pulp content of 1% and Br1x 11.0. Fruit juice 9.00
Obtained 0 kg.

This fruit juice is further treated with an ultrafiltration device (manufactured by Daicel Chemical Industries, Ltd.) having a polysulfone-based membrane, a molecular weight cut-off of 25,000, and a hollow fiber module membrane area of 60 rrr before forming the membrane. 8.000k
At the time of g, 2,000 kg of water was added and further permeated to obtain 1,000 kg of concentrated recovered fruit juice as a non-permeated liquid. The permeate was concentrated under reduced pressure to obtain 115 clear concentrated fruit juice having a very fresh taste. The concentrated recovered fruit juice was further centrifuged to obtain 800 kg of naturally cloudy fruit juice.

Example 2 Juice obtained by squeezing summer mandarin oranges with an in-line juicer was 93%
1/6 frozen concentrated fruit juice of summer mandarin oranges (54.5° to JAS standard Bri) which was instant sterilized at ℃, after cooling, coarse pulp was removed using a high-speed rotary centrifuge, concentrated under reduced pressure, and stored frozen.
15 kg was diluted to straight (Brix 11°). 75 kg of this was processed using an ultrafiltration device (manufactured by Daicel Chemical Industries, Ltd.) having a polysulfone membrane as a membrane material, a fractional molecular weight of 180,000, a holofiber type module before the membrane, and a membrane area of 1.5 M. When the amount of permeated liquid reached 60 kg, 20 kg of water was added, and the treatment was continued to collect 10 +r of fruit juice. Further, the pulp was removed by centrifugation to obtain 8 kg of naturally cloudy fruit juice as a non-permeate liquid. Further, the permeate was concentrated under reduced pressure to obtain clear, transparent fruit juice.

Example 3 Juice 1 obtained by squeezing Satsuma mandarin oranges using an in-line juicer
After pulverizing 00 kg using a high-speed rotating mill, it was instantaneously sterilized at 93°C, cooled, and the formed coagulate was removed using a high-speed rotating centrifuge. 80 kg of the obtained fruit juice was treated with a tubular type ultrafiltration device (manufactured by Daicel Chemical Industries, Ltd.) using a polysulfone-based membrane and a fractional molecular weight of FF 130,000 to obtain 10 kg of turbid recovered fruit juice.

Test Example Using the natural cloudy fruit juices of the present invention obtained in Examples 1 to 3 above, four types of drinks were prepared according to the formulations shown in Table 1 below.

(Margins below next summer) Table 1 (Parts by weight) (Margins below this page) Next, it was flash sterilized at 95℃, filled into 200-capacity juice bottles, and placed in the refrigerator (4℃) at room temperature at 37℃. A storage test was conducted under various conditions in a thermostatic chamber to observe changes in stability over time. The results are shown in Table 2.

(Margins below this page) 2 Table 1: No change +: Precipitation observed f: Significant precipitation Book: Most of the results showed that the natural cloudy fruit juice of the present invention was very stable even after 3 months. It remained turbid.

〔Effect of the invention〕

The present invention aims to obtain natural cloudy fruit juice with strong cloudiness and excellent stability through a relatively simpler operation than natural citrus fruit juice without using synthetic clouding agents, and also to produce clear fruit juice as a by-product. It can be used as a product as is, and has extremely high economic value.

Claims (1)

[Scope of Claims] 1. When producing citrus natural cloudy fruit juice from fruit juice obtained by squeezing citrus fruits, the fruit juice has a molecular weight cutoff of 20,
1. A method for producing cloudy natural citrus fruit juice, which comprises ultrafiltration through an ultrafiltration membrane of 000 to 80,000 to obtain cloudy juice as a non-permeate liquid. 2. The fruit juice to be ultrafiltered through an ultrafiltration membrane is the fruit juice obtained by squeezing citrus fruits, which is directly or micronized, then instant sterilized, and then cooled to produce agglomerated coarse pulp. A method for producing a natural cloudy citrus juice according to claim 1, wherein the citrus fruit juice is removed. 3. The method for producing natural cloudy citrus fruit juice according to claim 2, wherein the instant sterilization treatment is carried out at a temperature of 85° C. to 95° C. for a time of 20 seconds to 50 seconds.