GFSE 분말제재를 절인 배추에 대하여 0.1％, 0.3％ 및 0.5％씩 첨가하여 김치를 만들고 10％에서 숙성하면서 pH, 적정산도, 환원당 함량, 총균수, 젖산균수와 같은 품질 특성을 조사하였다. 숙성 기간이 경과함에 따라 김치의 pH는 감소하였는데, 대조구와 GFSE 분말제재 0.1％ 첨가구, 0.3％와 0.5％ 첨가구는 서로 비슷한 경향을 나타내었다. 대조구는 숙성 5일의 pH가 4.20으로 김치의 숙성 적기로 판단되는 범위에 도달하였는데

To investigate the antimicrobial activities and effect of grapefruit seed extract(GFSE) on the physiological function of microorganism, antimicrobial activity, fatty acids of bacterial cell lipid and amino acids of bacterial cell protein were measured. The change of cell morphotype was observed by transmission electron microscope. GFSE was very stable on the wide range temperture and pH. The growth rate of E. coli and B. suvtilis were decreased above 40ppm GFSE There fore, minimum inhibitory concentration (MIC) of the E. coli and B. subtilis to GFSE were determined around 40ppm. In the change of fatty acids quantities, hexadecanoate was significantly decreased on the treatment compared with control in case of E. coli, whereas tridecanoate was not detected in case of B. subtilis. In the change of amino acids quantities, alanine, glutamic acid, glycine, lysine were decreased on the treatment compared with control in case of E. coli and B. subtilis Transmission electron microsgraphs(TEM) showed the microbial cells were destroyed by GFSE.

To investigate the effect of several bactericides and fungicides against fruit & vegetable decay grapefruit seed extract(GFSE) was tested in a dilution solution. GFSE was shown to be effective against decay and rind breakdown and to extend the shelf-life of fruits and vegetables during storage and tiansport. Antimicrobial efficiency of GFSE on a wide spectra of gram + & - bacteria, moulds and yeasts was demonstrated by the measurement of minimal inhibitory concentrations performed (Bacteria 10-500ppm, Fungi:250-1,000ppm, Yeasts:100-250ppm). GFSE was separated and extracted into water-soluble fraction, water-insoluble and non-dialyzed fraction to isolate the antimicrobial substances. The water-soluble fraction showed the most active antimicrobial effect. The antimicrobial substances were isolated by gas chromatography. As the result of the isolation using GC, Peak-D was found to be the antimicrobial compound in GFSE. The identification of the most antimicrobial substance was carried out by using GC-MS.