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Dear Label_Name,

Greetings! I hope you are well.

I am writing on behalf of an international publishing house, Science and Education Publishing, USA (https://www.sciepub.com).

Science and Education Publishing (SciEP) is a multidisciplinary open access publisher of Journals covering the fields of Science, Technology and Medicine. All SciEP publications are subject to high-quality peer review, editorial and production processes and are freely available online.

Welcome to the April, 2013 edition of SciEP newsletter, providing monthly summaries of articles on science & education related topics of interest to scientist and professionals. The mission of our journals is to provide an open access forum for publishing new findings on issues pertinent to scientific and academic field. We also invite you to submit original research papers, review articles, short reports, or case studies are considered for publication in our Multidisciplinary Journals.

American Journal of Public Health Research
DOI: 10.12691/ajphr-1-1-3

The Implementation of a Tele-Homecare System with Service Oriented Architecture and HL7 Message Transmission Standard
Ching-Sung Wang

American Journal of Medical and Biological Research
DOI: 10.12691/ajmbr-1-1-2

The Influence of Ethanol on Pyruvate Kinases Activity in Vivo, in Vitro, in Silico
Lelevich Sergey Vladimirovich, Khrustalev Vladislav Victorovich, Barkovsky Eugene Victorovich, Shedogubova Tatyana Aleksandrovna

American Journal of Medical Sciences and Medicine
DOI: 10.12691/ajmsm-1-1-1

Clinical and Histological Features in Wegener Granulomatosis
Li Cavoli Gioacchino, Passantino Rita, Bono Luisa, Tortorici Calogera, Ferrantelli Angelo, Giammarresi Carlo, Rotolo Ugo

American Journal of Infectious Diseases and Microbiology
DOI: 10.12691/ajidm-1-1-2

The Curse of Lymphatic Filariasis: Would the Continual Use of Diethylcarbamazine Eliminate this Scourge in Papua New Guinea?
Anne Lanham, Lillian Mwanri

We have released issues of some journals on February 2013.
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American Journal of Medical Sciences and Medicine
American Journal of Medical and Biological Research
American Journal of Pharmacological Sciences
American Journal of Clinical Medicine Research
American Journal of Nursing Research
American Journal of Cancer Prevention
American Journal of Medicine Studies
American Journal of Infectious Diseases and Microbiology
American Journal of Cardiovascular Disease Research
American Journal of Biomedical Research
American Journal of Mechanical Engineering
American Journal of Microbiological Research
Journal of Preventive Medicine
American Journal of Food and Nutrition
American Journal of Hypertension Research
American Journal of Sports Science and Medicine
Journal of Cancer Research and Treatment
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Hypoiodous Acid and Drying Effects as Pretreatment of Shallot Paste on Physicochemical Properties During Room Storage

Ahmad Ni’matullah Al-Baarri*, Diana Nur Afifah, Ailsa Afra Mawarid, Muhammad Nur, Setya Budi Muhammad Abduh, Anang Mohammad Legowo, Mulyana Hadipernata, Elsa Chris Yudistra Sihite, Arya Rizky Priyatama, Dini Risanti, Veronika Angelica, Helena Ivana, Putri Aina Az Zahra

Food Technology Department, Faculty of Animal and Agricultural Sciences, Diponegoro University, Semarang, Indonesia

Abstract: Shallot is one of the most consumed commodities in Indonesia, but shallot undergo quality deterioration due to metabolic process and microbial growth. Turning shallots into a paste is a practical method for minimal processing. Therefore, this research was done for extend the duration of its shelf life using hypoiodous acid or HIO which was known as preservative. Hypoiodous acid is an oxyacid that acts as antimicrobial agent. As much as 0,2 mM HIO solution in water was prepared for soaking process of shallot while soaking in pure water was also conducted for producing control. Shallot paste was produced after dried for 3 hours and followed by packing in sealed-ziplock. Fifteen minutes steaming was then applied prior to storage in room temperature. Value of pH, total dissolved solid (TDS), L*, and browning index was analyzed descriptively based on the graph for each three days measurements. As result, HIO treatment stabilized the decrease of pH ranging from 6.6 to 6.2 after 30 days of storage while HIO hindered the increase in TDS even though until half of storage duration. All value of L* for both and HIO treatment showed a decrease starting from 45 to 17 but less decrease on its value was found in HIO treated shallot paste while browning index was also found as similar trends. As conclusion, HIO treatment might stabilized the change in pH, TDS, L*, and browning index. This research might open the knowledge of potent use of HIO in extension of shallot storage.

Keywords: drying, hypoiodous acid, shallot past

Received November 01, 2023; Revised December 01, 2023; Accepted December 10, 2023

Citation: Ahmad Ni’matullah Al-Baarri, Diana Nur Afifah, Ailsa Afra Mawarid, Muhammad Nur, Setya Budi Muhammad Abduh, Anang Mohammad Legowo, Mulyana Hadipernata, Elsa Chris Yudistra Sihite, Arya Rizky Priyatama, Dini Risanti, Veronika Angelica, Helena Ivana, Putri Aina Az Zahra, Hypoiodous Acid and Drying Effects as Pretreatment of Shallot Paste on Physicochemical Properties During Room Storage. Journal of Food and Nutrition Research, 11 (12). 715-718. January 2023. doi:10.12691/jfnr-11-12-2

1. Introduction

Shallot is one of the most commonly consumed commodity in Indonesia. Unfortunately, shallot could experience quality decreases due to metabolic process and microbial growth such as mold [1]. Up until now, preservation of shallot has always been done by salting, drying, pickling, and preserving them with acid. These preservation methods alter shallot’s taste and require a lot of process. Further processing of shallot by turning shallot into shallot paste is a way to minimally process shallot and make it practical. But in spite of that, processing shallot into shallot paste without further treatment will reduce the quality and also shallot paste’s shelf life. It is known that shallot paste can only last for 12 days during storage [2]. Therefore, further treatment is needed to extend its shelf life.

Hypoiodous acid is an oxyacid resulting from the combination of hydrogen peroxide (H₂O₂) and potassium iodate (KIO₃). This reaction begins with the activation of the peroxidase enzyme by H₂O₂ and when it is active, the peroxidase enzyme then oxidizes IO₃ to HIO [3]. Pretreatment technology using HIO has been proved to be potentially good in maintaining the quality of some food products, such as red chili paste (Capsicum annum L.), apple (Malus domestica), and snake fruit (Salacca edulis reinw.). HIO managed to inhibit microbial and chemical activities because HIO has potent microbicidal activity against bacteria [4]. In addition to giving shallot paste the HIO pretreatment, drying method is also able to extend shallot paste’s shelf life. Drying method will reduce the water content to a certain extent and suppress biological reactions and microbial growth of shallot paste [5]. Therefore, combining both HIO pretreatment and drying method could be able to extend shallot paste’s shelf life better.

Physicochemical properties are an important factor to decide the quality of food products, including shallot paste. Changes in physicochemical properties could be a sign of decrease in shallot paste quality. The use of HIO pretreatment and drying method combination is expected to maintain shallot paste’s physicochemical properties. Research on fresh shallots with ozone treatment has been done, but research on HIO treatment on shallot paste has never been done before. Based on those considerations, this study aims to identify the effect of HIO pretreatment and drying method combination on pH value, total dissolved solids, lightness, and browning index of shallot paste during storage.

2. Material and Method

2.1. Material

This research was done from July until October 2022 in Center of Research and Services Diponegoro University, Semarang, Indonesia. The sample used were shallots (Allium cepa L. var. aggregatum) obtained from a local grocery store. The selection was conducted using a previous research method [6]. Fresh and unblemished shallot, weighing between 6 and 8 g and averaging around 7 g, were purchased from a local grocery store that had distance about 2 kilometers from the research station. Shallot selection was conducted also using size criteria of about 3 to 5 cm wide in size. Other materials used in this research were hydrogen peroxide (Merck, Germany), KI (Merck, Germany), and chopper (Philips HR 1661, Hungary), continuous band sealer (FRB 770, Indonesia) oven (Corona DHG-9030A, Indonesia), analytical scale (Fujitsu FSR-A 200, Japan), pH meter (pH Meter 6-in-1 Pentype Tester, Taiwan), colorimeter (CHNSpec CS-10, China).

2.2. Method

The purchased shallots were then transferred to the research station with an aseptic container. Afterwards, the shallots were immediately given further treatment without any restorage.

2.2.1. HIO Preparation

The preparation of HIO was conducted using previous research [7] with modification. As much as 20 mM hydrogen peroxide (H₂O₂) and 20 mM potassium iodide (KI) was mixed in the similar volume to create a chemical reaction into HIO solution. The chemical reaction among this two substances generated HIO after 6 minutes reaction time as the following reaction:

I⁻(aq) + H₂O₂ ⥦ HIO + OH⁻

I2 (aq) + H₂O ⥦ HIO + I⁻(aq) + H⁺

5HIO ⥦ HIO₃ + 2I₂ + 2H₂O

The solution was then used for soaking process for 6 minutes. The solution could only be used for one time soaking. The drying process was done with a drying oven with air flow for 3 hours at 60oC. Finally, shallot was prepared for packing and preservation.

Shallots chopped using a chopper then put into retort pouches. The retort pouches filled with shallots paste were sealed using a continuous band sealer then steamed for 15 minutes. The steamed shallot was soaked in water to cool down the temperature and then stored at room temperature (27oC).

2.2.2. Application of HIO and Drying on Shallot

Application of HIO on shallot referred to previous research [8] with modification. HIO treatments were done by soaking samples in 0.2 mM HIO solution for 15 minutes. The samples were then drained and dried out with air circulation. Shallots with control and HIO treatment ready to be given the next treatment, which was drying.

Drying on shallot was conducted using method by previous researcher [9] with modification. Shallots were cut into thin circular shape using knife, then put evenly distributed onto each tray, based on the treatment. Both shallots were put in the heating drying oven at 60oC for 3 hours. After drying process, each samples chopped finely for around 2 minutes, then packed as much as 20 grams with 10x6 cm sealed-ziplock. Shallot paste in retort pouch was steamed in hot air for about 15 minutes. Shallot paste was stored at room temperature. Parameter analysis was done every 3 days for a month.

2.2.3. Color Changes Determination

Color changes determination referred to other researcher [10] using colorimeter method. Color data presented as L*a*b* value. Colorimeter was calibrated with standard black and white plates as provided by manufacturer. The value of browning index was then calculated using following formula:

[picture] | (1)

[picture] | (2)

2.2.4. The Value of pH Analysis

The value of pH analysis referred to previous researcher [11], using pH meter with modification. pH meter was calibrated with buffer solution at pH 4 and 7. Sample was extracted by dissolving 2 g of sample in 10 ml water and then extracted with filter cloth. Value of pH was analyzed by dipping the pH meter probe into the sample extract.

2.2.5. TDS Analysis

Total dissolved solid (TDS) analysis referred to previous reseacher [12], with portable TDS meter. Each samples were prepared as much as 2 g, then dissolved into 10 ml of aquadest. Samples were extracted with filter cloth. The analysis was carried out by dipping the probe of portable TDS meter into the sample.

2.2.6. Data Analysis

The characteristic of shallot paste was evaluated for 30 days. During this period, the shallot samples were evaluated every 3 days for quality characteristics using some of the methods described earlier. The shallot pastes were stored at room temperature.

Data analysis of color changes determination, pH analysis, TDS analysis and pH change in shallot was measured using Microsoft Excel 2019 then presented in a graph with error bars and scattered line.

3. Result and Discussion

3.1. The Value of pH Change in Shallot

Based on Figure 1, pH value of HIO-treatment shallot was more stable than control, resulting the range between 6.1 to 6.5. HIO has been known to inhibit browning reaction and pH reduction in fruit, such as snake fruit [13]. HIO is a compound that might inhibit bacterial and microbial growth, which can result in quality damage of shallot [14]. Shallot also contains antimicrobial properties, such as allicin. Allicin actively inhibits a wide range of gram-positive and gram-negative bacteria [15]. Combination of allicin and HIO as antimicrobial substances may preserve the quality of shallot for a long time. The more pH value reduction happens mean the higher acidity of shallot. Besides bacterial and microbial growth, quality damage of shallot can also be affected by metabolic reactions rate, so that in storage for several days, shallot’s pH value will be decreasing.

Figure 1. The Value of pH of shallot paste produced by hypoiodous acid treatment (HIO) and no treatment that was stored in room temperature

3.2. Total Dissolved Solid Shallot Paste

Figure 2. Total dissolved solid of shallot paste produced by hypoiodous acid treatment (HIO) and no treatment that was stored in room temperature

Based on Figure 2, total dissolved solids (TDS) of shallot with HIO treatment undergo steady increasing than control sample. This may happen because sample with HIO treatment contains more ion than the control sample. Hypoiodous acid contains several ions such as iodide and hydrogen ion [16]. Rich concentration of ions in shallot can be attributed to its ability to ionize easily [17]. Ionic concentration is part of the conductivity measurement. Conductivity properties related to dissolve solutes. The higher ion concentrated in shallot means it contains lot of dissolved solids.

3.3. L* Value Shallot

Based on Figure 3, the L* value of shallot paste with HIO treatment and control treatment decreased during storage. Shallot paste with HIO treatment in lower temperature has a highest L* value while shallot paste with control treatment in room storage has a lowest L* value. Shallot paste with HIO treatment have a higher L* value than shallot paste with control treatment. HIO treatment could slow down the decrease in L* value. HIO is a compound that can inhibit browning enzyme so the decrease in L* value was lower than without HIO [18]. Shallot paste in room temperature had higher L* value than those of low temperature. Storage temperature affect the rate of browning reaction. Higher storage temperature cause a greater decreased in shallot L* value [19].

Figure 3. L* value of shallot paste produced by hypoiodous acid treatment (HIO) and no treatment that was stored in room temperature

3.4. Browning Index

Figure 4. Browning index of shallot paste produced by hypoiodous acid treatment (HIO) and no treatment that was stored in room temperature

Browning index of shallot with control pretreatment was higher and more unstable than sample with HIO pretreatment (Figure 4). Anthocyanin pigments and chlorogenic acid in shallots undergo a browning reaction which causes a change in the color of the shallot paste. Anthocyanin and chlorogenic acid in onions may undergo oxidation reaction with the polyphenol oxidase enzyme to produce melanoidin which gives a brown color [20]. This browning reaction runs faster at higher temperatures.

4. Conclusion

Based on this research, it can be concluded that shallot paste with HIO pretreatment was more stable in pH value, TDS value, L* value, and browning index than those of control. This stability proved the benefit of HIO as preservative substance as it could preventing browning and acidity on shallot.

References

[1]   | Kusmali, M., Ahmad, U. and Darmawati, E., “The Effect of Curing and Leaves Cutting in Longterm Storage of Shallot.” In IOP Conference Series: Earth and Environmental Science, IOP Publishing, 1-13.
[2]   | Tantalu, L, Isrofatin, I. G. Bano, and Y. D. Kaka. “Effectiveness of standing pouch shallot paste packaging at frozen temperature and room temperature storage”, In National Industry Technology Seminar Proceeding, 2-7.
[3]   | Gusrianto, W. A., S. Fatimah-Muis, A. N. Al-Baari, and A. M. Legowo. “Hypoiodous Acid Effect on Antioxidant Activity and Total Microbes in Salak Pondoh in Room Temperature of Storage”. Food Technology Application Journal, 7(3). 122-126.

[4]  
Derscheid, R. J., A. v. Geelen, A. R. Berkebile, J. M. Gallup, S. J. Hostetter, B. Banfi, P. B. McCray, and M. R. Ackermann. “Increased concentration of iodide in airway secretions is associated with reduced respiratory syncytial virus disease severity”, American Journal of Respiratory Cell and Molecular Biology, 389-397.

[5]   | Napitupulu, F. H. and Y. M. Atmaja. “Design and testing of corn dryer with cabinet dryer with cabinet dryer type for 9 kg per-cycle capacity”. Dynamic Journal, 2(8). 32-43.
[6]   | Mukhopadhyay, S., Ukuku, D. O., Olanya, O. M., Sokorai, K., & Fan, X. “Effects of pulsed light and aerosolized formic acid treatments on inactivation of Salmonella enterica on cherry tomato, reduction of microbial loads, and preservation of fruit quality”, Food Control, 13. 1-8. June. 2022.

[7]  
Al-Baarri, A. N., Legowo, A. M., Hadipernata, M., Broto, W., Auliyana, E., Puspitoasih, A. D., Wratsongko, A. C. D., Izzati, L., Michael, Handoko, Y. D. P., Yusuf, M., Wahda, M. H., and Pangestika, W. “Inhibitory Action of Hypoiodous Acid (HIO) against Browning on Apple through the Analysis of Lightness Appearance”, In IOP Conference Series: Earth and Environmental Science, IOP Publishing, 1-5.

[8]  
Al-Baarri, A. N., Legowo, A. M., Hadipernata, M., Broto, W., Auliyana, E., Puspitoasih, A. D., Wratsongko, A. C. D., Izzati, L., Michael, Handoko, Y. D. P., Yusuf, M., Wahda, M. H., and Pangestika, W. “Inhibitory Action of Hypoiodous Acid (HIO) against Browning on Apple through the Analysis of Lightness Appearance”, In IOP Conference Series: Earth and Environmental Science, IOP Publishing, 1-5.

[9]  
Al-Baarri, A. N. M., Legowo, A. M., Wratsongko, A. C. D., Puspitoasih, A. D., Izzati, L., Auliana, E., Michael, Pangestika, W., Hadipernata, M., and Broto, W. “Effect of hypoiodous acid (HIO) treatment on color and pH changes in snake fruit (Salacca edulis Reinw.) during room temperature storage “In IOP Conference Series: Earth and Environmental Science, IOP Publishing, 1-5.

[10]   | Tang, R., Peng, J., Chen, L., Liu, D., Wang, W., and Guo, X. 2021. Combination of Flos Sophorae and chili pepper as a nitrite alternative improves the antioxidant, microbial communities and quality traits in Chinese sausages. Food Research International, 141, 110131.

[11]  
Al-Baarri, A. N. M., Legowo, A. M., Wratsongko, A. C. D., Puspitoasih, A. D., Izzati, L., Auliana, E., Michael, Pangestika, W., Hadipernata, M., and Broto, W. “Effect of hypoiodous acid (HIO) treatment on color and pH changes in snake fruit (Salacca edulis Reinw.) during room temperature storage “In IOP Conference Series: Earth and Environmental Science, IOP Publishing, 1-5.

[12]   | Iqbal, A., Farheen, R., and Parween, R. “Comparative evaluation of total iron, vitamin c and total phenolic contents in fresh juices of apple (malus pumilla) grown in pakistan”, FUUAST Journal of Biology, 9(1). 29-32. June. 2019.

[13]  
Al-Baarri, A. N. M., Legowo, A. M., Wratsongko, A. C. D., Puspitoasih, A. D., Izzati, L., Auliana, E., Michael, Pangestika, W., Hadipernata, M., and Broto, W. “Effect of hypoiodous acid (HIO) treatment on color and pH changes in snake fruit (Salacca edulis Reinw.) during room temperature storage “In IOP Conference Series: Earth and Environmental Science, IOP Publishing, 1-5.

[14]   | Bafort, F., Parisi, O., Perraudin, J. P., and Jijakli, M. H. “Mode of action of lactoperoxidase as related to its antimicrobial activity: a review.” Enzyme research, 1-13. Sep. 2014.
[15]   | Bao, H. N. D., Hien, P. T., & Le Quyen, V. “Antioxidant and antimicrobial activities of hydrophilic extracts from shallot and garlic bulbs, and their effects on round scad during ICED storage. The Annals of the University Dunarea de Jos of Galati”, Fascicle VI-Food Technology, 44(1). 26-44. 2020.

[16]  
Muntean, N., Thuy, L. B., Kály-Kullai, K., Wittmann, M., Noszticzius, Z., Onel, L., and Furrow, S. D. “Measurement of Hypoiodous Acid Concentration by a Novel Type Iodide Selective Electrode and a New Method To Prepare HOI. Monitoring HOI Levels in the Briggs–Rauscher Oscillatory Reaction”, The Journal of Physical Chemistry A, 116(25). 6630-6642. May. 2012.

[17]   | Udoetok, I. A. “Characterization of ash made from oil palm empty fruit bunches (oefb)”, International Journal of Environmental Sciences, 3(1). 518-524. Nov. 2012.

[18]  
Al-Baarri, A. N., Legowo, A. M., Hadipernata, M., Broto, W., Auliyana, E., Puspitoasih, A. D., Wratsongko, A. C. D., Izzati, L., Michael, Handoko, Y. D. P., Yusuf, M., Wahda, M. H., and Pangestika, W. “Inhibitory Action of Hypoiodous Acid (HIO) against Browning on Apple through the Analysis of Lightness Appearance”, In IOP Conference Series: Earth and Environmental Science, IOP Publishing, 1-5.

[19]   | Setyadjit, S., Sukasih, E., and Arif, A. B., "Prediction of storage life of shallot powder by using acceleration method", International Journal of Agriculture System, 5(2). 140-153. Des. 2017.
[20]   | Sukasih, E., Permata, A. C., and Bintang, M. “Kinetics of shallot powder (Allium ascalonicum) quality change during storage and its shelf life” In IOP Conference Series: Earth and Environmental Science, IOP Publishing, 1-8.