JPH0541942A - Green vegetable packed in package and it production - Google Patents

Abstract

PURPOSE:To produce the subject vegetable holding its raw green color, having excellent preservability and useful for canned foods, etc., by cultivating the green vegetable in a specific aqueous culture solution, charging and sealing the obtained green vegetable in a package, and subsequently thermally sterilizing the sealed green vegetable. CONSTITUTION:A green vegetable such as spinach is cultured in an aqueous culture solution containing K and Zn in higher concentrations than those of the K and Zn in a standard culture solution composition, and the obtained green vegetable is packed in a package and sealed. The sealed vegetable is thermally sterilized to obtain the objective vegetable. The K and Zn in the aqueous culture solution are preferably contained in concentrations of 10-20 times and 100-200 times standard concentration, respectively.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a green vegetable in a packaging container which maintains the green color of raw green vegetable even after high temperature sterilization and a method for producing the same.

[0002]

2. Description of the Prior Art It is well known that when green vegetables are canned, the green color of the vegetables after the high temperature sterilization process is significantly fading to brown. As one method for maintaining the green color of canned vegetables, there is a method disclosed in Japanese Patent Laid-Open No. 59-120046.
In this method, vegetables are bleached in water containing zinc or copper ions at a temperature of about 150 to 212 ° F. and then canned by a conventional method.

[0003]

The above-mentioned conventional method is to recover the green color once lost by the processing during the canning process of vegetables, but the degree of the recovery is such that the green color of raw vegetables can be partially suppressed. However, it does not fully satisfy the demands of consumers for the color of vegetables, such as the fact that the green color of raw vegetables does not return or there is a food hygiene problem. Therefore, an object of the present invention is to provide a green vegetable in a packaging container and a method for producing the same, which keeps the green color of the raw green vegetable almost even after heat sterilization at high temperature.

[0004]

Means for Solving the Problems The present inventors have conducted various experiments and studies in order to achieve the above-mentioned object, and as a result, have combined the concentrations of potassium and zinc in a hydroponic solution at a concentration higher than the standard composition. When the vegetables were hydroponically cultivated, they found that the green color of the vegetables after the heat sterilization treatment was extremely good, and reached the present invention.

The green vegetables in the packaging container of the present invention for achieving the above object are green vegetables hydroponically cultivated in a hydroponic solution in which the concentration of potassium and zinc in the hydroponic solution is higher than the standard culture solution composition. After being filled and sealed in a packaging container, it is heat-sterilized by a conventional method. In addition, the method for producing a green container-containing green vegetable of the present invention which achieves the above-mentioned object is to hydroponic green vegetables in a hydroponic solution in which the concentration of potassium and zinc in the hydroponic solution is higher than the standard culture solution composition. Cultivated,
The obtained green vegetables are filled in a packaging container, sealed, and then heat-sterilized by a conventional method.

The present invention is different from the conventional method in which a special treatment for keeping a green color is carried out in a process of canning vegetables grown and cultivated by an ordinary method, unlike the conventional method. This is a treatment for holding, and is characterized in that the harvested vegetables themselves have the property of not losing their green color even when subjected to high temperature sterilization treatment.

In the present invention, hydroponic culture is carried out by a conventional method according to a known hydroponic culture method depending on the type of vegetables. In the present specification, the standard culture solution composition means the following composition. Standard culture solution composition of the water culture solution _{NH 4 NO 3 3mM NaN 2 PO} 4 · 2H 2 O 1mM K 2 SO 4 2mM CaCl 2 · 2H 2 O 4mM MgSO 4 · 7H 2 O 2mM Fe ( by Fe-EDTA) 3ppm B (by H ₃ BO ₃₎ (by _{MnCl 2 · 4H 2 O) 0.5ppm} Mn ( by _{ZnSO 4 · 7H 2 O) 0.5ppm} Zn 0.05ppm Cu ( by _{CuSO 4 · 5H 2 O) 0.02ppm} Mo (Na ₂ by MoO ₄ · 2H ₂ O) 0.01ppm

In the present invention, vegetables are grown and cultivated in a hydroponic solution in which the concentrations of potassium and zinc in the standard culture solution composition are higher than the above concentrations. The type and concentration of the components other than potassium and zinc in the hydroponic solution are basically those of the above standard culture solution, but are not strictly limited to this, and the types and concentrations of the components other than potassium and zinc are used. There is no problem even if it is changed a little within a range that does not impair the purpose of keeping the green color.

With respect to the concentrations of potassium and zinc, it has been known that the lower leaves of vegetables cause yellowing and poor growth, etc. When the excess concentration is taken into consideration, potassium is a standard It is preferable that the concentration is 10 to 20 times, and the concentration of zinc is 100 to 200 times the standard concentration or less.

As the green vegetables to which the present invention is applied, for example, spinach, green pea, komatsuna, green beans, green cabbage and the like are suitable. The present invention can be applied to green vegetables contained in other packaging containers such as retort pouches in addition to these canned green vegetables.

[0011]

INDUSTRIAL APPLICABILITY According to the present invention, green vegetables were hydroponically cultivated in a hydroponic solution in which the concentrations of potassium and zinc in the hydroponic solution were higher than the standard culture solution composition. Green vegetables have a higher pH than control vegetables hydroponically cultivated in a standard culture solution, and the green color immediately after heat sterilization at 120 ° C for 4 minutes is very good, and the good green color is practically stored in a refrigerator. It can be held for a sufficient period.

[0012]

[Examples] Engae and sweet potato leaves of the Convolvulaceae family were cultivated by hydroponic culture in a hydroponic solution containing various concentrations of potassium and zinc higher than standard concentrations. The experimental results for sweet potato leaves are described below, but almost the same results were obtained for Ensai. Experimental Materials and Methods (1) The cultivation test was conducted twice. Table 1 shows the compositions of potassium (denoted as K) and zinc (denoted as Zn) in the culture solution. Standard concentrations are given for each element not shown.

[0013]

[Table 1]

In test 1 (summer), potassium was used as standard 1
/ 3, standard, 5 times, 10 times, 20 times, each group of zinc standard, 50 times, 100 times, 200 times amount, zinc is set to 100 times amount of standard and phosphorus is 1 / of the standard. 3, a standard, a 5-fold, a 10-fold, and a 20-fold groups (for the purpose of checking antagonism with zinc) and a group in which potassium, calcium, and magnesium were ⅓ of the standard were set. In Test 2 (winter season), a group of sweet potato leaves cultivated in a standard medium was foliarly sprayed with potassium or zinc, again potassium standard, 10 times, 20 times amount zinc standard, 1
A group in which the amounts of 00 times and 200 times were combined, the potassium salt was replaced with KCI to obtain the standard, 10 times, and 20 times,
A group in which zinc was standard, a combination amount of 200 times, and a group in which zinc was replaced with ZnCl ₂ were provided.

In the table, K10 + Zn100 indicates that potassium is 10 times as much as the standard medium and zinc is 100 times as much as the standard medium, and hereinafter referred to as K10 + Zn100 section. P
Although KH ₂ PO ₄ is generally used as the salt, it was difficult to determine whether it was the effect of phosphorus or the effect of potassium, so in this experiment we decided to use NaH ₂ PO ₄ .2H ₂ O.

(2) The foliar application was carried out by using a shoulder type sprayer once a week from 4 weeks after the sweet potato leaves were sufficiently grown, and No. 28 was ZnSO ₄ .7H ₂ O 0.2% solution,
No. 29 is K ₂ SO ₄ 0.4% liquid, No. 30 is ZnS
The O ₄ · 7H ₂ O 0.2% and K ₂ SO ₄ 0.4% of the mixture was sprayed.

(3) For sterilization, the leaves were placed in a retort pouch, vacuum-sealed, and then heated at 120 ° C. for 4 minutes in the retort with a target of F 0 = 4. The green degree was measured by a chlorophyll meter, a visual evaluation method, a color difference meter, or the like.

Experimental Results Looking at the growth state of sweet potato, the growth of the above-ground part was slightly inferior in the K20 section, and the lower leaves were damaged. This tendency was more remarkable in KCl than in conventional K ₂ SO ₄ . The Zn200 zone was slightly inferior, but the conventional ZnSO
_No difference was observed between ₄ and ZnCl ₂ . Root growth is K
It was slightly inferior in 1/3 ward and part of Zn200 ward. No difference in growth was observed from the plots with different P concentrations, but K 1/3 +
In the Ca 1/3 + Mg 1/3 ward, the growth of the above-ground part and roots was considerably inferior. In the Zn foliar spray and K + Zn foliar spray plots, lesions appeared on the leaves. Therefore, good results were not obtained for foliar application. PH of fresh leaves of sweet potato, fresh leaves and 1
The chlorophyll meter measured values immediately after heating at 20 ° C. for 4 minutes are shown in Tables 2 and 3.

[0019]

[Table 2]

[0020]

[Table 3]

When the potassium salt was K ₂ SO ₄ , the fresh leaf pH was higher in the higher potassium concentration group, but the opposite tendency was observed when the potassium salt was KCl. The measured value of chlorophyll meter has some variation, but K measured by K ₂ SO ₄
10 + Zn100, K10 + Zn200, K20 + Zn
In the 100, K20 + Zn200 zone, the measured value immediately after the heat treatment at 120 ° C. for 4 minutes and the B / A residual rate were high.
In the case of KCl, the value was high in the Zn high concentration group, but the value on the chlorophyll meter decreased as the potassium concentration increased.

No clear relationship was found between the phosphorus concentration and pH and the values measured by the chlorophyll meter. Tables 4 and 5 show visual evaluation points of greenness immediately after heat treatment of sweet potato leaves at 120 ° C, 2 minutes, 120 ° C, 4 minutes, 120 ° C, 6 minutes.

[0023]

[Table 4]

[0024]

[Table 5]

No. 18 to N immediately after heating at 120 ° C. for 4 minutes
K20 ward of o.21, K10 + Zn100 ward of No.34,
No.35 and No.43 K10 + Zn200 ward, No.37
In the K20 + Zn100 group, the evaluation point was 4, and in the potassium high-concentration group and the zinc high-concentration group, the degree of green remaining was particularly good. Particularly excellent evaluations were not obtained from the phosphorus concentration section and the K20 section using KCl.

Further, in order to clarify the difference in color tone, Tables 6 and 7 show the color tone immediately after heating by L, a and b. 12
When the measured values at 0 ° C. for 4 minutes were observed, the a value was small in the potassium high concentration group and the zinc high concentration group of the potassium concentration setting groups (No. 1 to No. 39) by K ₂ SO ₄ . As a result, N
K20 + Zn200 section of o.21, K20 + Z of No.37
In the n100 section and the K20 + Zn200 section of No. 38, the a value is small, and therefore, it can be said that the green color remains most stable.

[0027]

[Table 6]

[0028]

[Table 7]

As described above, the visual evaluation points immediately after the heat treatment and the measured values by the chlorophyll meter were almost the same. KCl
A certain tendency was not recognized from the K concentration setting group and the P concentration setting group by. Although the difference between ZnSO ₄ and ZnCl ₂ is not clear, ZnSO ₄ was slightly better. In the above measurement, the sample having a good color tone immediately after the heat treatment was stored in the refrigerator, and the change in color was measured with time (visual evaluation point).

[0030]

[Table 8]

No.34 K10 + Zn100 section and No.3
The K20 + Zn100 ward of 7 had a visual evaluation score of 3 until 14 days later.
Keeping No. 35 and No. 43 with K10 + Zn200 ward
No.38 K20 + Zn200 ward, No.20 K20 +
Even after 20 days, the Zn 100 ward maintained a relatively good green color with a visual evaluation point of 3. The above tendency was also recognized from the small a value in Tables 9 and 10 in which the change in color tone is represented by L, a, and b.

[0032]

[Table 9]

[0033]

[Table 10]

The results of the above experiments are summarized as follows. When the conventional K ₂ SO ₄ was used as the potassium salt of the hydroponic solution, the higher the K concentration, the higher the pH of the fresh leaves. Immediately after the heat treatment, the green color remained in the high potassium concentration group. Regarding zinc, the higher the concentration of zinc, the more stable the green color remained immediately after the heat treatment, and especially the residual chlorophyll a was confirmed by thin layer chromatography. as a result,
K10 + Zn100 ward, K10 + Zn200 ward, K20
The + Zn100 section and the K20 + Zn200 section were very good. The good green color of the high potassium / high zinc region after heating was kept in the refrigerator for 20 days or more.

Concerning the concentrations of potassium and zinc, potassium is considered to be 10 to 20 times the standard concentration, taking into consideration excess damage.
It was considered preferable that the concentration of zinc be 100 to 200 times or less the standard concentration.

When KCl is used as the potassium salt, K ₂ S
The results were not as good as with O ₄ . Regarding the zinc salt, there was no great difference between ZnSO ₄ and ZnCl ₂ , but ZnSO ₄ was slightly better.

Claims (3)

[Claims] 1. A green vegetable hydroponically cultivated in a hydroponic solution in which the concentration of potassium and zinc in the hydroponic solution is higher than that of a standard culture solution. Green vegetables in a packaging container. 2. Green vegetables are hydroponically cultivated in a hydroponic solution in which the concentration of potassium and zinc in the hydroponic solution is higher than the standard culture solution composition, and the obtained green vegetables are filled into a packaging container and sealed. After that, a method for producing green vegetables in a packaging container, which is heat-sterilized by a conventional method. 3. A green vegetable hydroponically grown in a hydroponic solution in which the concentration of potassium and zinc in the hydroponic solution is higher than that of the standard culture solution composition.