HO CHI MINH CITY UNIVERSITY OF TECHNOLOGY AND EDUCATION KING MONGKUT’S UNIVERSITY OF TECHNOLOGY THONBURI A THESE MAJORS CHEMISTRY FOOD TECHNOLOGY DOSES OF GAMMA IRRADIATION AFFECTING POSTHARVEST QUALITY OF FINGEROOT DURING STORAGE ADVISOR:APIRADEE UTHAIRATANAKIJ CANDIDATE:HUYNH MINH NGUYET SKL 0 0 6 1 7 3 2019 do an DOSES OF GAMMA IRRADIATION AFFECTING POSTHARVEST QUALITY OF FINGERROOT DURING STORAGE MISS HUYNH MINH NGUYET A THESIS SUBMITTED IN PARTIAL FULFILMENT OF THE REQUIREMENT FOR THE DEGREE OF BACHELOR OF SCIENCE (FOOD TECHNOLOGY) SCHOOL OF BIORESOURCES AND TCHNOLOGY KING MONGKUT’S UNIVERSITY OF TECHNOLOGY THONBURI HO CHI MINH CITY UNIVERSITY OF TECHNOLOGY AND EDUCATION 2019 do an I ABSTRACT Gamma irradiation has become one of the effective food technology to reduce risk of food poisoning and preserve quality. The effect of doses of gamma irradiation on postharvest quality has been repoted in various fruits and vegetables. This study was aimed to investigate the changes in postharvest quality of fingerroot rhizome and fresh – cut fingerroot after irradiation by different doses of gamma ray. In experiment on fingerroot rhizome, all samples were treated with gamma ray at 0 (control), 1.0 kGy and then stored at 13°C for 12 days of storage.
The results showed that there were no significant differences in physical properties of fingerroot which were weight loss and colour peel change value during storage. Moreover, gamma irradiation did not affect on total phenolic content, total flavonoid content and DPPH radical scavenging activity of fingerroot rhizome as compared to the control. However, samples at doses of 2.0 kGy resulted in the reduction of vitamin C content stored at 13°C. Thus, gamma irradiation with dose of 1.0 kGy obtained better conditions in controlling postharvest quality of fingerroot rhizome than other treatments.
On the other hand, all samples of fresh – cut fingerroot were irradiated by gamma ray with doses of 0 (control), 0.0 kGy and stored at 4°C during 8 days. The data revealed that irradiation did not obviously change in colour value of fresh – cut fingerroot at storage period, in comparison with the unirradiated sample. Neither radiation treatment nor storage condition had siginificant effect on browning value, sensory evaluation and internal gases inside package of fresh – cut fingerroot. All treatmetns increased total phenolic content, but vitamin C content decreased gradually during storage and reached its lowest values at the end of the storage period.
In addition, fresh – cut fingerroot treated with 0.0 kGy showed a significant reduction microorganism more than the non – irradiated sample at every stages of period. Therefore, gamma irradiation at 0.5 kGy effectively maintained postharvest quality and inhibited microbial load of fresh – cut fingerroot as compared to the control stored at low temperature. Keywords: fingerroot, gamma irradiation, rhizome, fresh – cut do an II ACKNOWLEDGEMENT I am deeply thanked to King Mongkut’s University of Technology Thonburi (KMUTT), School of Bioresourses and Technology for giving me a chance to take an internship course and complete my thesis for Bachelor’s degree during 6 months. I also want to thank to my Institute – Ho Chi Minh City University of Technology and Education (HCMUTE) – introduced this associate study program to me, therefore I could apply and experience to make oversea research in Thailand.
I would like to express my grateful appreciation to my Advisor, Assoc. Apiradee Uthairatanakij, who took care of me and also constantly encouraged me throughout the study. I am grateful to Thailand Institute of Nuclear Technology (Public Organization), Nakhonnayok Province, where provided technical support for my research. I would like to express my grateful appreciation to all postharvest technology laboratory members and staffs for all training and convenience.
I thank all seniors from different countries who are usually willing to support for my study, especially in Pathology and Physiology Laboratory. Finally, I would like to thank those closest to me who provided their emotional support, entertainment, time and advice. do an III CONTENTS PAGE ABSTRACT i CONTENTS iii LIST OF TABLES vii LIST OF FIGURES viii LIST OF ABBREVIATIONS ix CHAPTER 1.3 Scope to study 2 1.1 Constituent of fingerroot 3 2.2 Biological activity of fingerroot 5 2.2 Anti - inflammatory activity 6 2.2 Ionizing radiation 8 do an IV 2.3 Doses used in radiation processing 8 2.4 Scope of irradiation 10 2.1 Control of insects (disinfestation) 10 2.2 Reduction of microbial load 11 2.3 Prolonging shelf – life 11 2.4 Improvement of product quality 11 2.5 Effect of gamma irradiation on post – harvest quality of fruits and vegetables 12 2.1 Physical properties changes 12 2.2 Chemical properties changes 12 2.3 Microbial properties changes 17 3. MATERIALS AND METHODS 20 3.2 Experiment 1: Effect of gamma irradiation doses on physico – chemical changes of fingerroot rhizome 20 3.2 Colour peel change 20 3.3 Preparation of Extracts 21 3.4 Total phenolic content 21 3.5 Total flavonoid content 21 3.6 DPPH Radical Scavenging Activity 21 3.3 Experiment 2: Effect of gamma irradiation on postharvest quality of fresh – cut fingerroot 22 3.1 Sensory evaluation 22 do an V 3.2 Internal gases inside package 22 3.3 Determine browning value 23 3.5 Research working place 23 4.
RESULTS AND DISCUSSION 24 4.1 Experiment 1: Effect of gamma irradiation doses on physico – chemical changes of fingerroot rhizome Error! Bookmark not defined.1 Weight loss Error! Bookmark not defined.2 Color peel change Error! Bookmark not defined.3 Total phenolic content (TPC) Error! Bookmark not defined.4 Total flavonoids content (TFC) Error! Bookmark not defined.5 DPPH Radical Scavenging Activity Error! Bookmark not defined.6 Vitamin C content Error! Bookmark not defined.2 Experiment 2: Effect of gamma irradiation on postharvest quality of fresh – cut fingerroot Error! Bookmark not defined.1 Color change Error! Bookmark not defined.2 Determine browning value Error! Bookmark not defined.3 Sensory evaluation Error! Bookmark not defined.4 Internal gases inside package Error! Bookmark not defined.5 Total phenolic content (TPC) Error! Bookmark not defined.6 Vitamin C content Error! Bookmark not defined.7 Microbial analyses Error! Bookmark not defined. CONCLUSION AND SUGGESTIONS 41 5.1 Effect of gamma irradiation doses on physico – chemical changes of fingerroot rhizome 41 do an VI 5.2 Effect of gamma irradiation on postharvest quality of fresh – cut fingerroot 41 5.3 Suggestion 41 REFERENCES 42 do an VII LIST OF TABLES TABLE PAGE Table 1 Irradiation doses for food processing (Ehlermann, 1989 and Jones, 1992) 9 Table 2 Effect of gamma irradiation on L* value of fingerroot rhizomes stored at 13°C Error! Bookmark not defined. Table 3 Effect of gamma irradiation on a* value of fingerroot rhizomes stored at 13°C Error! Bookmark not defined. Table 4 Effect of gamma irradiation on b* value of fingerroot rhizomes stored at 13°C Error! Bookmark not defined.
Table 5 Effect of gamma irradiation on sensory evaluation (appearance, odour, overall acceptance and overall browning) of fresh - cut fingerroot stored at 4°C Error! Bookmark not defined. Table 6 Effect of gamma irradiation on microbial counts of fresh - cut fingerroot stored at 4°C Error! Bookmark not defined. do an VIII LIST OF FIGURES FIGURE PAGE Figure 1 Fingerroot (Boesenbergia pandurata)(Marsya, et al., 2018) 3 Figure 2 Chalcone, flavanone and flavone structures (Agus, et al., 2014) 4 Figure 3 The major compounds of essential oils in fingerroot (Agus, et al., 2014) 5 Figure 4 Effect of gamma irradiation at various doses on weight loss of fingerroot rhizomes during storage at 13°C Error! Bookmark not defined. Figure 5 Effect of gamma irradiation doses on total phenolic contents of fingerroot rhizome during storage at 13°C Error! Bookmark not defined.
Figure 6 Total flavonoids content of fingerroot was determined by aluminium chloride method and expressed as mg of quercetin equivalent (QE)/g dry mass of sample Error! Bookmark not defined. Figure 7 Effect of gamma irradiation on DPPH radical scavenging activity of fingerroot Error! Bookmark not defined. Figure 8 Effect of gamma irradiation on ascorbic acid content of fingerroot rhizome Error! Bookmark not defined. Figure 9 Effect of gamma irradiation doses on L* value of fresh - cut fingerroot stored at 4°C Error! Bookmark not defined.
Figure 10 Effect of gamma irradiation doses on a* value of fresh - cut fingerroot stored at 4°C Error! Bookmark not defined. Figure 11 Effect of gamma irradiation doses on b* value of fresh - cut fingerroot stored at 4°C Error! Bookmark not defined. Figure 12 Effect of gamma irradiation doses on browning index of fresh - cut fingerroot stored at 4°C Error! Bookmark not defined. Figure 13 Effect of gamma irradiation doses on O2 concentrations inside fresh - cut fingerroot package stored at 4°C Error! Bookmark not defined.
Figure 14 Effect of gamma irradiation doses on CO2 concentrations inside fresh - cut fingerroot package stored at 4°C Error! Bookmark not defined. Figure 15 Effect of gamma irradiation on total phenolic contents of fresh – cut fingerroot stored at 4°C Error! Bookmark not defined. do an IX Figure 16 Effect of gamma irradiation on vitamin C content of fresh - cut fingerroot stored at 4°C Error! Bookmark not defined. do an X LIST OF ABBREVIATIONS et al.
= From Latin, abbreviation of et (“and”) and alii (“others”) Gy = Gray kGy = Kilogray °C = Degree Celcius i.e = From Latin, abbreviation of id (“that”) and est (“is”) cm = Centimeter µg = Microgram v/v = Volume/ volume CFU/g = Colony Forming Units per gram µl l-1 = Micro litre per litre kg = Kilogram ml = Milliliter nm = Nanometer mg = Milligram g = Gram M = Molarity µg/ml = Microgram per milliliter O2 = Oxygen CO2 = Carbon dioxide h = Hour do an XI g/kg = Gram per kilogram DNA = Deoxyribonucleic acid Est. = Estimated WHO = World Health Organization FAO = Food and Agriculture Organization do an 1 CHAPTER 1 INTRODUCTION 1.1 Research Background Fingerroot (Boesenbergia pandurata) is used as a mixture of herbal medicine or as a spice in cooking (Tewtrakul, et al. In addition, the fingerroot is also utilized as natural dyes and traditional remedies (Ongwisespaiboon and Jiraungkoorskul, 2017). In the primary health care project of Thailand, the rhizome of this plant is used for the treatment of dyspepsia.
As regards to its biological activities, fingerroot exhibited antibacterial, antifungal, anti – inflammatory, analgesic, antipyretic, antispasmodic, antitumor and insecticidal activities (Tewtrakul, 2003). The rhizome of fingerroot is generally used as a culinary spice in Thailand and also has been used for the treatment of oral diseases (i., dry mouth), stomach discomfort, stomach pain, leucorrhoea, diuretic, dysentery and inflammation. The rhizomes are used in traditional medicine as antiseptic and for the treatment of stomachache, diarrhea, dermatitis, dry cough and mouth ulcers (Saralamp, 1996 and Heyne, 1987), gastrointestinal disorders and post – natal treatment (Burkill, 1935). However, harvested rhizomes of fingerroot loss their quality during storage.
Food irradiation is a physical process involving treatment of food with ionizing radiation. In this process, products are exposed to ionizing energy, either from gamma rays or a high - energy electron beam or powerful X – rays for a specified time (FDA, 1986). At low doses, irradiation extends a product’s shelf life. At higher doses, this process kills insects, moulds, bacteria and other potentially harmful microorganisms.
Its main uses are reduction in spoilage and pathogenic organisms, inhibition of ripening and sprouting processes, and insect disinfestation. Chemical changes in the treated foods are small, and expert committees have concluded that they carry no special nutritional problems (David, 1994). Irradiation is highly effective for inactivation of foodborne pathogens and parasites in various vegetables (Bidawid, 2000). Several previous reports have shown that irradiation is a suitable method to control sensory quality and shelf life of fruits and vegetables, however, it received less attention for medicinal plants, especially on fresh herbs.
Therefore, this study aimed to examine the efficay of gamma rays on postharvest quality of fingerroot rhizome and fresh cut fingerroot. To study the effect of gamma irradiation doses on physico – chemical changes of fingerroot rhizomes stored at low temperature. To investigate the effect of gamma irradiation doses on quality changes of fresh – cut fingerroot.3 Scope to study 1.