Medicinal effect of cabbage is connected with favorable chemical elements of carbohydrates, mineral matter, vitamin C. Vitamin U is an important component in therapy of gastric ulcer, while sulphury heterosis enable cabbage leaves to have an antiseptic effect. The aim of this work was to examine antimicrobial activity of the fresh cabbage juice immediately after squeezing and after keeping it in a refrigerator for 6 months.

Examination was made with ten microorganisms: Escherichia coli 95, Staphylococcus aureus ATCC 6538, Pseudomonas auruginosa, Klebsiella pneumoniae, Sarcina litea 9341, Salmonella enteritidis, Bacillus subtilis S, Bacillus subtilis 841, Aspergillus niger, Saccharomyces cerevisiae, Candida albicans using the method of cellulose disk, in agar according to Ph. Jug IV.

The fresh cabbage juice sample had an effect on all the tested microorganisms except on Saccharomyces cerevisiae. After six months of keeping samples at temperature of 8°C, antimicrobial activity was present, but with somewhat smaller inhibition zones and with more expressed bacteriostatic activity.

Key words: cabbage, juice, antimicrobial properties, substrate, activity, resistance.

Cabbage represents one of the oldest and most important vegetable species due to its outstandingly high nutritional and biological value and large growing areas, too. A range of characters has contributed to wide-spread growing areas of cabbage, such as: differing vegetation length and differing biological characteristics (Lazić et al., 1993) so that cabbage is being grown nearly everywhere in the country, particularly in R. Serbia on some 25.000 ha (Maksimović, 1991). Being very tasty, nutritional and of suitable chemical composition, cabbage has a remarkable role in human nutrition. Cabbage does not have so high nutritional value, but it does have high nutritive-physiological significance for a range of mineral matter and vitamins it contains. For specific vitamin U ("Brasicin") first discovered in cabbage, which is highly efficient in gastric ulcer prevention and the like, cabbage has gained in significance.

Being so, a new cabbage storage assortment has been introduced, thereby enabling good supplies of fresh cabbage all year round (Cervenski et. al., 1994) which contributes to better man's nutrition, especially in wintertime. This particularly applies to cold areas where cabbage cannot do well all year round, but has to be stored.

This vegetable is mostly used as fresh, pickled or dried. Due to its numerous medicinal properties, cabbage has a broad use in medicine (Veljković and Bisenić, 1988). The best medicinal characteristics pertain to the freshly squeezed cabbage juice (Jovanović, 1987). Its medicinal value is attributed to the vitamin U (methyl methyonine-sulfone) and to some other components participating in the complex with this vitamin and contributing to cabbage fresh juice medicinal effects including even anticancerous ones. Additionally, cabbage is also externally applied to wounds, ulcers and affected areas.

Allowing for high medicinal effects of fresh cabbage juice, the goal of this study has been set accordingly, meaning additional assessment of its curative effects and investigation of its antimicrobial activity.

Antimicrobial effects of cabbage juice were studied in two stages. The first implied cabbage production till its technological maturity and sampling needed for the second stage in which cabbage juice antimicrobial characters were subjected to lobarotary testing. Cabbage was produced in open filed, on production-experimental plots at Trbusani in the vicinity of Čačak on the smonitza type of soil. The hybrid "Rinda" introduced from Holland as a selection of the "Royal sluis" seed company, was used for the experiment. The hybrid "Rinda" belongs to white cabbage - Brassica deracea var. capitata L. formu alba. Medium-early earliness, good internal structure, high quality, 4-8 kg mass per cabbage, achieves high and stable yields in different environmental conditions, suitable for production all through vegetation season, used fresh, but may be kept well in open or when stored.

Production proceeded in summer and autumn. Transplants were planted on the vegetation area sized 70 x 45 cm with density of 33.000 plants/ha. Common cultural practices for this crop were regularly applied during summer and autumnal production. At the stage of cabbage technological maturity, sampling was made for purpose of laboratory investigations and cabbage antimicrobial characters determinations.

Laboratory investigations were carried out at A.D. Zdravlje - Quality Control Sector of the pharmaceutical and chemical industry in Leskovac. Cabbage juice was first squeezed and antimicrobial properties then tested.

In order to test cabbage juice antimicrobial activity, the following microorganisms were used: Escherichia coli 95, Staphylococcus aureus ATCC 6538, Pseudomonas aeruginosa, Klebsiella pneumoniae, Sarcina lutea 9341, Salmonella enteritidis, Bacillus subtilis 841, Aspergillus niger, Saccharomyces cerevisiae, Candida albicans.

Antimicrobial features were tested on fresh cabbage juice, then with juice after three months of keeping in refrigerator at +8°C and after six months of keeping, as a variant of testing them in refrigerator at +8°C. In this regard, diffusion method on cellulose disk according to Ph.Jug. IV, was applied. As a medium for bacteria growth, " ANTIBIOTIC MEDIUM " 1 (Difko Laboratories Detroit Michigen USA), "TRIPTON SOJA AGAR" for fungi (Torlak, Beograd) and Saccharomyces cerevisiae "SABORO DEKSTROZNI AGAR" for yiest (Torlak, Belgrade) were used. To 100 ml medium cooled at 45°C 1 ml of concentrated suspension, obtained through microorganism suspension from sloped agar in 10 ml 0.9% NaCl was added. 10ml of sown medium was spilled in Petry dishes each 10 mm in diameter. Disks "ANTIBIOTIKA TEST BLATTCHEN" (Schleicher and Schuell, Dassel Germany) 12.7 mm in diameter were directly submerged into cabbage juice, placed on the sown medium and incubated for 18-24 hours at 37°C. After incubation completion, the diameter of microoganisms growth inhibition zone was read on the apparatus "FISHER-LILLY ANTIBIOTIC ZONE READER" (Fisher Scientific Co USA).

Diffusion method applied to cellulose disk with use of test microorganisms Eccherichia coli 95, Staphylococcus aureus ATCC 6538, Pseudomonas aeruginosa, Klebsiella pneumoniae, Sarcina litea 9341, Salmonella enteritidis, Bacillus subtilis S. Bacillus subtilis 841, Aspergillus niger, Saccharomyces cerevislae, Candida albicans helped examine antimicrobial activity of fresh cabbage juice as well as of that obtained from cabbage kept at +8°C for three and six months, respectively. The results obtained are given in Tab.1.

The analysis of results on fresh cabbage juice antimicrobial activity suggests a declined sensitivity in the series, as follows: Staphylococcus aureus ATCC 6538, Pseudomonas aeruginosa, Escherichia coli 95, Klebsiella pneumoniae, Aspergillus niger, Candida albicans, Sarcina litea 9341 The yiest Saccharomyces cerevisiae was found to be resistant to cabbage juice. The results on testing cabbage juice obtained after three and six months have shown a uniform activity. After six months, we also tested this activity on Salmonella enteritidis, Bacillus subtilis S. Bacillus Subtilis 841. A specificity of interest is that cabbage juice kept for six months had a stronger antimicrobial impact on Candida albicans than that kept for three months, showing resistance or no activity. These results are in agreement with those obtained by Gudžić et al., 1998.

Based upon the investigations conducted on active properties of cabbage juice, the following conclusions may be drawn:

In general, cabbage juice displayed antimicrobial activity on the microorganisms studied. Of all the microorganisms tested, only the yiest Sacharomyces cerevisiae indicated resistence. Lower antimicrobial activity existed in the cabbage juice kept for three months than in the fresh one, Candida albicans was also found to be resistant to the cabbage juice kept for three months. Antimicrobial activity of cabbage juice kept for six months was nearly the same as that of cabbage juice kept for three months, and antimicrobial activity of cabbage juice kept for six months exerted higher sensitivity of Candida albicans contrary to that of cabbage juice kept for three months, causing its resistance.

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