Nata de coco rich in high dietary cellulose microfiber of low calories and thus suitable to be promoted as healthy drink is derived from bacterial fermentation of coconut water (an agricultural by-product). In this study the optimal amount of nata de coco to be added to mao juice was investigated. Nata de coco was produced by using Acetobacter xylinum TISTR 86 cultured at 30oC for 15 days in a plastic box containing culture medium which was composed of 92.5% coconut juice 0.5% ammonium sulfate 5.0% sucrose and 2.0% vinegar. Hedonic scale (1-9 point) sensory evaluation was used to select the optimal ratio of nata de coco from the 3 ratios of 5 10 and 15% to be added to mao juice. Based on taste and overall liking the most favorable mixture is to add nata de coco of 10% to mao juice. Finally the chemical physical and microorganism properties of mao juice with nata de coco in a 180 ml clear-glass bottle were measured after it was stored at room temperature for 1 month. This mixture product was found to beneficially contain fiber two times the amount of that of sole mao juice. The result suggests that these variable parameters of mixture product were accepted base on the Thai Community Product Standard (486/2547).

This study focused on screening and identification of lactic acid bacteria with antimicrobial activity against Escherichia coli from milk samples. There were 250 isolates showing different antimicrobial activities. Five isolates with predominant anti-E. coli efficiency were chosen for the study of bacteria identification bacterial growth as well as the stability in pH change heating and proteolytic treatment. The sequences of 16s rDNA indicated that selected isolates were Lactobacillus sp.. The antimicrobial efficiency described in the term of Antimicrobial Index (AI) ranged from 0.63 to 0.84. However the anti-E coli activity did not change when performing the test under proteinase-treated condition and high temperature-treated condition. Conversely the pH adjustment of cell-free bacterial culture to 7.0 demolished their antimicrobial activity. This data implied that their antimicrobial activities were results of acidic condition produced by lactic acid bacteria. From this study the selected lactic acid bacteria showed their potential as a starter culture for fermented foods.

A system response of a near infrared (NIR) instrument sometimes changes depending on measuring conditions such as warming up time room temperature and the others. In the last peach experiment we measured NIR spectra over 3 days and spectral differences were observed between spectra measured at the first day and those at the second and third days. Therefore a simple method of system response compensation was examined. As a result of principle component analysis (PCA) of second derivative (2D) spectra of peaches samples were separated into two groups the first-day measured samples and the second and third-day measured ones on the plane consisted of PC1 and PC2. On the hypothesis that average 2D spectrum of each group should be almost the same the difference of the average 2D spectra (2D spectrum) was calculated. Using 2D spectrum 2D spectra of the first-day samples were adjusted to those of the other samples. The data set including the adjusted one is called “compensated 2D data set” hereafter as compared with “original 2D data set”. As results of partial least square (PLS) regressions based on the original and compensated 2D data sets and Brix value of peaches good SEPs of 0.98 °Brix for both cases could be obtained. The number of factors for the calibration model in case of compensated 2D data set was smaller than that in case of original one. It was concluded that the method using 2D spectrum could be used to compensate the difference of system response of an NIR instrument.

The purpose of this research was to investigate cooling water profile that effect to coefficient of performance of spilt type air- conditioning system. Air conditioner size of 12000 Btu/h was used in this experiment. There are three experiment of cooling water profiles in this work such as water spray water drop and heat exchanger profile. The ambient temperature conditions were controlled at 35 40 43 and 45 oC. The results of this study were found that heat exchanger profile had the highest average coefficient of performance and energy efficiency as 4.94 and 9.15 Btu/Wh which increased as 20.1% and 8.47% respectively when comparing with the normal working.

This paper presents reliability evaluation in distribution system with distributed generation. The main objective is to minimize the customer interruption cost subject to given number of distributed generation. The minimization problem for customer interruption cost in solved by the developed tabu search algorithm together with reliability worth analysis that provide an indirect measure for cost implication associated with power outages. The developed methodology is tested with a distribution system of Roy Billinton Test System (RBTS) bus 2 consist of 15 buses and 22 load points. Numerical results from the tests demonstrate that the optimal distributed generation placement can be used to promote reliability of the distribution systems.