Effect of Postharvest Storage Quality of Atemoya Treated with Multiple Oxidants Containing Chlorine

Focusing on Modern Food Industry (FMFI), Volume 5 2016 doi: 10.14355/fmfi.2016.05.001

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Effect of Postharvest Storage Quality of Atemoya Treated with Multiple Oxidants Containing Chlorine Oxide by Using Electrolytic Deep Sea Water J.X. Liu1; N.T. Chen1; H.C. Huang1; C.H. Yen1; C.H. Chen1; W.W. Liao2; J.W. Yang2; S.M. Chang2; C.Y. Chang3* Department of Life Science, National Taitung University, Taiwan

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Department of Applied Science, National Taitung University, Taiwan

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Center for General Education, National Taitung College, Taiwan

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*Corresponding author: cyc1136@ntc.edu.tw Abstract According to the data of Taiwan's Food and Agriculture Agency, sugar-apple is one of the important economic fruit in Taiwan.

In 2001, the external sales were 5,458 tones and the export value reached to 223.16 million Taiwan dollars. It is the second largest export fruit, only less than bananas. Atemoya was the main sugar-apple species and occupied 99.3 %. The other sugar-apples were only 0.7 %. To explore the main possible reasons, Atemoya did not occur easily the dumb-fruit and blacken situation during the low-temperature storage. Therefore, Atemoya was more easily exported to overseas than the other sugar-apples.

This study is expected to enhance the brine of deep seawater resource utilization by using the low valuable concentrated brine as an electrolyte material to produce an oxidant by an electrolysis procedure. Its high oxidation capacity to kill or inhibit microorganisms and to remove or inhibit the production of ethylene extends the lifetime of Atemoya.

Experiments used 50 ppm multi-oxidant to do the sonication spray treatment (0 ~ 15min) and collocated with fruit bag and PE sealed bag for preservation under at 11 ℃controlled temperature. The results showed that there were the significant differences existing between the added multi-oxidant group and the controlled group in the inhibitory effect and the appearance color of fresh preservation. But there was no significant difference in sweetness and hardness. Therefore, this study had revealed that chlorine dioxide multi-oxidant could effectively sterilize the surface of Atemoya, enhance the preservation degree, and extend the shelf-life. Those results are benefit to the overseas sales and enhance economic value.

Keywords Electrolytic Deep Sea Water; Chlorine Dioxide; Atemoya

Introduction With the development of society, many people have realized pathogens on the food would cause food contamination and foodborne illness. Food preservation has been attached to importance by consumers and chlorine dioxide has been proven in killing pathogens for food preservation [1, 2].

Although desalination technology is often questioned to be a controversial issue due to high costs, high energy consumption and concentrated brine release, it is a water resourcing technology positively developed in arid areas of the world. The brine produced by deep seawater reverse osmosis (RO) desalination processes causes high costs, high energy consumption and low economic value. Therefore, we utilized electrolytic catalysis technology and the concentrated brine from the deep seawater plant in Taiwan to develop a brine resource utilization process, producing a multi-oxidant with disinfection efficacy, containing chlorine dioxide (ClO2), chlorine (Cl2), ozone (O3) and hypochlorous acid (HOCl).

Many studies have proved that chlorine oxide can kill many pathogens including bacteria, virus, fungi and spores.

In addition, the safety of chlorine oxide has been recognized by World Health Organization (WHO) as A1 disinfecting reagent and chlorine oxide is an ideal disinfecting reagent of chlorine-based disinfectants [3-5].

Chlorine dioxide has been used in the preservation of food including vegetables, fruits, fish and meat. This 1

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treatment on fruits and vegetables would not be harmful for human and it would not influence plant fiber, flavor, and nutrients of fruits and vegetables. This treatment on fish and meat not only can remove fishy orders, but also can inhibit the growth of microorganism for food shelf-life extension. In this study, we focused on the effect of postharvest storage quality of Atemoya, which is a special fruit in Taitung [6, 7], treated with multiple oxidants containing chlorine for 16 days.

Experimental Procedure Material Atemoya was a hybrid of two fruits which were the sugar-apple (Annona squamosa) and the cherimoya (A. cherimola). Atemoya was seeding in artificial vegetative propagation which was an asexual reproduction to avoid heritage varieties of fruits. The best quality of Atemoya was harvesting from December to April.

Method 1) Preparation of Multiple Oxidants Containing Chloride Dioxide Use deep sea water as a raw material to produce multiple oxidants containing chloride dioxide which is manufactured by electrolytic procedure. The new electrolysis protocol modified from electrolysis diaphragm of Model Hooker S-3 was used in this study. Sodium chloride is used to be electrolyzed to produce numerous strong oxidants including Cl2, ClO2, O3, and H2O2. The positive pole, which is made of a titanium rod and titanium mesh coated with Pd, and insoluble anode, which is made of Rh with (ISA) as catalyst, were separated by using the diaphragm of Nafion N-2030 membrane in the electrolyte chamber [8].

2) Treatment with Chloride Dioxide and Analysis The Atemoya in paper bags harvested in the morning were treated with RO water or various concentration of chloride dioxide (50 ppm and 200 ppm) via ultrasonic atomization (Sumo, Ultrasonic Nebulizer V-15) for 15 minutes and then the fruits were sealed in PE bags or carton. Atemoya fruits were randomized to one of 6 groups (Group A: Carton/RO; Group B: RO/PE bag; Group C: Carton/50 ppm ClO2; Group D: PE bag/50 ppm ClO2; Group E: Carton/200 ppm ClO2; Group F: PE bag/200 ppm ClO2) and each group contained 6 fruits. All test groups were refrigerated at 11 °C for 12 days. After 12 days, the fruits were trigger repining at room temperature for 4 days to determine fruit diameter, weight, hardness, soluble solids content, ripeness, fruit appearance and flesh appearance on Day 16.

Results and Discussion On the 16th day, hardness value of control groups and test groups declined lower than 3N (Fig. 1). The result demonstrated that all Atemoya fruits became ripe on the 16th day.

A. Carton/Control B. PE bag/Control C. Carton/50ppm D. PE bag/50ppm E. Carton/200ppm F. PE bag/200ppm FIGURE 1. COMPARISON ON FLESH FIRMNESS OF ATEMOYA FRUITS ON DAY 16

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The weight loss percentage of all Atemoya fruits sealed in PE bags (Group B, D and F) was lower than Atemoya fruits stored in cartons (Group A, C and E) on the 16th day (Fig. 2). The result demonstrated that Atemoya fruits sealed in PE bag had better water-holding capacities.

%

A. Carton/Control B. PE bag/Control C. Carton/50ppm D. PE bag/50ppm E. Carton/200ppm F. PE bag/200ppm FIGURE 2. WEIGHT LOSS PERCENTAGE OF ATEMOYA FRUITS ON DAY 16

There was no significant deference in soluble solids content between Atemoya fruits treated with chlorine dioxide (Group B, C, D, E and F) and control group (Group A and B) on the 16th day (Fig. 3), so treating with chlorine dioxide would not change the flavor of Atemoya.

A. Carton/Control B. PE bag/Control C. Carton/50ppm D. PE bag/50ppm E. Carton/200ppm F. PE bag/200ppm FIGURE 3. SWEETNESS PERFORMANCE OF ATEMOYA FRUITS ON DAY 16

In the period of ripening, the fungi infected area of Atemoya fruits in control group (PE bag/RO) was more than other groups. The decaying area of Atemoya fruits in test group chlorine dioxide (Group C, D, E and F) was less than control groups and the appearance of fruits maintained green color. There was no difference in flesh color of Atemoya fruits between all groups. The result showed that chlorine dioxide could inhibit fungi infection and the fruits treated with chlorine dioxide had more economic value in the market.

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A Carton/Control (Day 1)

B PE bag/Control (Day 1)

A Carton/Control (Day 12)

B PE bag/Control (Day 12)

C Carton/50ppm (Day 1)

C Carton/50ppm (Day 12)

D PE bag/50ppm (Day 1)

D PE bag/50ppm (Day 12)

E Carton/200ppm (Day 1)

F PE bag/200ppm (Day 1)

E Carton/200ppm (Day 12)

F PE bag/200ppm (Day 12)

A Carton/Control (Day 16)

B PE bag/Control (Day 16)

C Carton/50ppm (Day 16)

D PE bag/50ppm (Day 16)

E Carton/200ppm (Day 16)

F PE bag/200ppm (Day 16)

FIGURE 4. APPEARANCE OF ATEMOYA FRUITS ON DAY 16

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A Carton/Sarcocarp of Control (Day 16)

B PE bag/Sarcocarp of Control (Day 16)

C Carton/Sarcocarp of Control (Day 16)

B PE bag/Sarcocarp of 50ppm (Day 16)

E Carton/Sarcocarp of 200ppm (Day 16)

F PE bag/Sarcocarp of 200ppm (Day 16)

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Conclusion The optimal condition of Atemoya postharvest storage is Atemoya fruit treated with multiple oxidants containing chlorine dioxide manufactured by electrolytic deep sea water and sealed in PE bags. This method of preservation has a great economic value for Atemoya promotion.

ACKNOWLEDGMENT

This study is supported by a grant from the Ministry of Economic Affairs of Taiwan under the contract of 102-EC17-A-32-S1-230.

REFERENCE

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[3] FDA, ‘Secondary direct food additives permitted in food for human consumption’, 1995, Fed. Regist. 60, 11899–11900.

[4] FDA, USDA, CDC, ‘Guidance for industry-guide to minimize microbial food safety hazards for fresh fruits and vegetables’, 1998. <http://www.cfsan.fda.gov/_dms/prodguid.html>.

[5] EPA, ‘Pesticides: topical and chemical fact sheets. Anthrax spore decontamination using chlorine dioxide. Environmental Protection

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[6] ‘The promotion crops “Custard Apple”’, Taitung area farmer's association, Taiwan, <http://www.eastfa.org.tw/ main.asp?body_sel=3_4_2_2#>. (in Chinese) [7] J.X. Lee, C.S. Yang, L.X. Ko, ’ 1-MCP and storage temperature effect on the physiology of atemoya after ripening’, The conference special issue for the research and application on the treatment technology of garden product postharvest, 2005, 79-90, Taiwan agricultural research institute. (in Chinese) [8] C.Y. Chang: ‘Evaluation on the efficiency of anode and electric-dialytic membrane of electrolytic equipment producing chlorine dioxide’, 2007, Industrial Technology Research Institute, Taiwan. (in Chinese)

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