본 연구에서는 건열처리를 통해 알팔파 종자에 접종된 Bacillus cereus ATCC 12480, Listeria monocytogenes ATCC SSA81, Staphylococcus aureus ATCC 6538, Escherichia coli O157:H7 ATCC 43894, Salmonella Typhimurium ATCC 14028을 발아율에 영향 없이 불활성화 시키는 조건(65oC 에서 21일, 70oC에서 16일, 75oC에서 10일, 80oC에서 7일)을 조사하였다. 알팔파 종자를 6-7 log CFU/g 수준으로 접종 하고 65, 70, 75, 80oC로 건열처리 한 후, 발아율을 확인 하였다. 알팔파 종자의 발아율은 시장에 유통되고 있는 알 팔파 새싹의 발아율 기준인 70%로 설정하였다. 알팔파 종 자에서 B. cereus는 65oC에서 21일, 70oC에서 18일, 75oC 에서 14일, 80oC에서 4일, Listeria monocytogenes는 65oC에서 21일, 70oC에서 18일, 75oC에서 12일, 80oC에서 7일, S. aureus는 65oC에서 18일, 70oC에서 18일, 75oC에서 11 일, 80oC에서 4일, E. coli O157:H7은 65oC에서 21일, 70oC 에서 18일, 75oC에서 12일, 80oC에서 6일, Sal. Typhimurium 은 65oC에서 24일, 70oC에서 22일, 75oC에서 14일, 80oC 에서 7일 이상 건열처리 하였을 때 완전히 불활성화 되었 다. 모든 균주는 65oC에서 80oC로 온도가 상승할 때 특정 온도에서 세균의 90%를 죽이는 데 필요한 시간인 D-값 (R2=0.5656−0.7957)이 유의미하게 감소하였다(P<0.05). 80oC 에서 7일간 건열처리 하였을 때 발아율이 70% 미만으로 감소하였기 때문에 75oC에서 14일간 건열처리 하는 것이 알팔파 종자의 안전성을 확보하는데 있어 가장 효과적인 방법이다. 이 연구는 알팔파 종자의 안전성을 확보하고 일 정한 품질의 새싹을 생산하는데 기초자료로 이용될 것으 로 기대된다.

This study investigated the effect of dry heat treatment (DHT) on the physicochemical properties of hard type (HR) and floury type (FR) rice to improve the processing aptitude of rice flour. The rice flour was heated at 130oC for 0, 2 and 4 hours, and the color value, water absorption index (WAI), water soluble index (WSI), swelling power, solubility, pasting properties, particle shape and the X-ray diffraction were measured. After DHT, the L value of rice flour decreased, and the b value increased. The WAI, WSI, swelling power and solubility of HR and FR increased with the increase of treatment time. The cold viscosity and setback increased, while breakdown decreased. Cracks and lumps formed with fine particles were observed. The X-ray diffraction pattern was A-type, while the diffraction intensity decreased. According to the results of the two-way analysis of variance (ANOVA) test, the hydration and pasting properties were significantly different between HR and FR and were affected by DHT time. The results suggest that the properties of modified rice flour by DHT can be used in the food industry.

The mixed atomized iron powders with 0.3% graphite and 1% Ni powders were cold pressed and sintered at for 30 min under pure Ar gas atmosphere. Some of the sintered specimens were intercritically annealed at and quenched in water (single quenching). The other sintered specimens were first fully austenized at and water quenched. These specimens were then intercritically annealed at and re-quenched in water. The experimental results showed that the wear coefficient effectively decreased in the double quenched specimen.

This study was conducted to investigate changes in seed vigor based on temperature of dry heat and duration treatment of watermelon seeds and examine the effect on percent of emergence and seedling vigor. When the upper limit temperature of dry heat treatment was raised to 80℃, the percent of the germination decreased. Moreover, T50 was delayed as the upper limit temperature of dry heat treatment increased. The higher the upper limit temperature of dry heat treatment and the longer the treatment period, the higher the percentage of abnormal seedlings. The optimum upper limit temperature for dry heat treatment was 72℃, and the treatment period was five days. Seed vigor was better maintained at 30℃, 45℃, and 52℃, followed by stepwise exposure to high temperatures of 72℃, the upper limit of dry heat treatment, rather than dry heat treatment at a high temperature of 72℃ for 5 days from the initial stage of treatment. When the fungicide was added during the dry heat treatment process, the germination percentage decreased and the percent of the abnormal seedling percentage increased. However, the addition of 10 mg/kg fungicide did not significantly reduce seed vigor.

The purpose of this study was to develop the cost-effective and efficiency seed longevity prediction method of rice (Oryza sativa L.) germplasm for viability monitoring. To find an optimum predicting method for rice seed longevity at genebank, an accelerated ageing (AA) test, a controlled deterioration (CD) test and a dry-heat treatment (DHT) were conducted to the four groups of rice germplasm based on ecotype, such as Indica, Japonica, Javanica and Tongil type. Among the three artificial aging treatments, the dry-heat treatment of 36 hours at 90°C is suggested as a routine predictive test method of rice germplasm longevity at a genebank. The distribution of germination rate on 3,066 accessions which conserved 26.5 years at 4°C showed similar trend with the result of distribution by dry-heat treatment at 90°C on 36 hours using 106 accessions of rice selected samples which composed four ecotype groups. The results show that the dry-heat treatment affect not only predicting the rice seed longevity but also determining effective interval for monitoring germination of rice germplasm in genebanks.