Development of Rapid Detection System for Monitoring Thai Jasmine Rice (KDML 105 Variety) Supply Chain | |
| Author | Atcharaporn Khoomtong |
| Call Number | AIT Diss. no.FB-15-01 |
| Subject(s) | Rapid Detection System Thai Jasmin Rice Supply chain management |
| Note | A dissertation submitted in partial fulf illment of the requirements for the degree of Doctor of Philosophy in Food Engineering and Bioprocess Technology, School of Environment, Resources and Development |
| Publisher | Asian Institute of Technology |
| Series Statement | Dissertation ; no. FB-15-01 |
| Abstract | Nowadays, food quality and safety are crucial issues worldwide as they are closely related to consumers’ health and well-being. Being the staple food in Asian countries, rice quality and safety are important issues because consumers are becoming more concerned about the quality and safety of the food they consume. The main objective of this research was to design a low-cost portable device based on the colorimetric method for rapid amylose content determination for commercial rice that involves measuring the absorbance of the starch- iodine complex. Initially, ten individual kernel s of milled rice were boiled in the hot water, cooled and filtered followed by the addition of 0.1 M HCl solution and subsequently stained with iodine- potassium iodide. Next, the amylose iodine complex was measured using the portable amylose content meter (PAC Meter). The device with dimensions of 170x220x80 mm, and weighing 600 grams to be used for the analysis of amylose content in milled rice was designed following the colorimetric method. The PAC meter consisted of a light source, filter, sample cell (where the starch-iodine complex solution resulting from the reaction of amylose and iodine is to be placed), phototransistor detector (i.e. solar cell), exit slit of size 1x5 cm and a digital multimeter. A phototransistor detector was used for light intensity detection. It could generate current, and the voltage could be measured using a digital multimeter. This device can measure both AC and DC (i.e. 9 V DC battery), allowing the device to be transported and used under any field conditions. A regression model was developed based on the measurement of the amylose-iodine complex from the selected five rice varieties and used for the formulation of the standard curve for PAC meter. The regression equation for the sta ndard curve was: Amylose content (%) = (Absorbance+0.036) / 0.017 having a multiple coefficient of determination (R 2 ) of 0.99 at p <0.01. The amylose content of the samples was strongly and positivel y correlated with the absorbance values with 99% correlation. Furthermore, to study the precision of PAC meter, eleven Thai rice varieties were selected (n=10). The measurements were made using PAC meter that showed acceptable precision based on the international me asurement system as <20% coefficient of variation (%CV) was achieved. The accuracy of PAC meter measurements was confirmed by comparing the results with those obtained by the conventional method, which was not significantly different ( p <0.05). The PAC meter is, therefore, applicable in the prediction of amylose content in rice, is economical, rapid, straightforward, portable, and reliable. In addition, this development can decrease the analysis period of over 24 hours to less than an hour. Secondly, the alkali spreading value (ASV), a nother index of cooking quality, is an inverse indicator of the gelatinization temperature (GT) of milled rice. The amendments made to this method during the recent years focused on the subjective interpretation of the results. This study also investigated the optimum concentration of KOH solution to decrease the process duration of the original method. In the modified ASV method using the different KOH concentration (ASV 3h ) of 5.1% w/w, the extent of disintegration of the rice kernels during soaking in the alkali solution was not different from that of conventional ASV (23 hrs) . In addition, this modification of ASV (3hrs) may enable high-speed and accurate adulteration testing of Thai Jasmine rice in rice mills, decreasing the testing duration from 23 hours to 3 hours. The DNA method is the best method for the detection of the adulteration of Thai Jasmine rice (KDML105) with other rice varieties (PTT1 and CNT1). However, the analysis involved is very expensive, time-consuming, and require highly skilled operators, making the method unsuitable in the industry. The alkali spreading value (ASV) with the new KOH iv concentration of 5.1% is a good alternative method for the detection of adulteration as exemplified by its high accuracy, economy, simplicity and ease of use in rice milling industry This work also includes the development of Food Safety Management System (FSMS) based on Hazard Analysis Critical Control Point principle (HACCP) for rice milling production which is currently a major challenge for the Thai economy. The aim is to propose control measures for all hazards (i.e. physical, chemical and biological hazards) that could be encountered in all processing lines of the rice mill. In this regard, gap analysis was carried out on rice milling production plants in Thailand to identify requirements for a prerequisite program (PRPs), the facility was upgraded. Fina lly, to verify the effectiveness of FSMS, a local medium scale rice milling enterprise in th e Northeast area of Thailand was selected for a case study. This study was conducted by monitoring the environment of the rice production facility, as well as by auditing and verifying the FSMS. Air sampling, water sampling, swabbing of equipment surfaces, hand of operators and packaging materials revealed a microbiota which was consistent with the milled rice product. The monitoring parameters showed that the microbiota in paddy and milled rice is within critical limits conforming to the safety standards for milled rice. This was confirmed by the results of laboratory analysis of paddy and milled rice, which further showed that the presence of Bacillus cereus decreased drastically after FSMS. In addition, Escherichia coli and Staphylococcus aureus , were not detected in the samples. Toxic fumigant residue was previously found in milled rice at amounts ranging from 0.1 to 70.8 mg/kg as bromide ion, which was no longer detected in milled rice samples after the implementation of FSMS. Moreover, the level of alflatoxin in the paddy samples was 6.8 to 22.8 mg/kg and was not detectable in milled rice. Implementation of FSMS was therefore found to be an effective quality management system for ensuring the safety of milled rice during the traditional processing of paddy into milled rice. This study leads to a better appreciation of the benefits of FSMS implementation in rice milling, which include improving the physical, chemical, and biological properties of milled rice and, in turn, increases the customer satisfaction in the global food trade. |
| Year | 2015 |
| Corresponding Series Added Entry | Asian Institute of Technology. Dissertation ; no. FB-15-01 |
| Type | Dissertation |
| School | School of Environment, Resources, and Development (SERD) |
| Department | Department of Food, Agriculture and Natural Resources (Former title: Department of Food Agriculture, and BioResources (DFAB)) |
| Academic Program/FoS | Food Engineering and Bioprocess Technology (FB) |
| Chairperson(s) | Athapol Noomhorm |
| Examination Committee(s) | Anal, Anil Kumar;Soni, Peeyush |
| Scholarship Donor(s) | RTG Fellowship |
| Degree | Thesis (Ph. D.) - Asian Institute of Technology, 2015 |