Study On Fresh-Keeping Of Eggs With Chinese Herbal Extracts

This paper regards fresh intraday eggs as the tested materials. A series of experiments were conducted to research the quality change of eggs with the method of film coating, by measuring the human's sensory (albumen, yolk, band) and eggs physicochemical index (highness of air chamber, weight losing rate, yolk coefficient, content of dense albumen, Haugh unit), under the conditions of 25℃and 50%-70% of relative humidity during a 35-day's storage.The main content of this article are three aspects as follow:(1) In the different time and temperature, we extracted the effective antimicrobial components of eighteen kinds of Chinese herbal plants with 60%-95% concentration alcoholic solvent, including Lauraceae Cinnamomum camphora L., cassia presl; Labiatae Agastache rugosa, Folium perlliae L. and Rabdosia serra Hara; Caprifoliaceae Honeysuckle; Myrtaceae Syzygium aromaticum; Nymphaeaceae Nelumbo lotus; Zingiberaceae Zingiber; Cucurbitaceae Momordica; Compositae Taraxacum; Leguminosae sp. Radiz glycyrrhizae; Liliaceae Allium sativum; Theaceae tea; Cyperaceae Heleochairs tuberose Schult; Violaceae Viola yedoensis Makino; Saururaceae Houttuynia cordata thrunb.We used those extracts for fresh-keeping with the method of film coating. The results show that these alcoholic extracts of Chinese herbal medicine have a certain preservation effect on eggs. The fresh-keeping effect of Honeysuckle, Syzygium aromaticum L., Taraxacum mongolicum and Ginkgo biloba L. extracts are the best and the rate of fresh-egg is 100% after storage of 35 days.(2) We mixed the four best extracts in 1:1 by volume, in accordance with the same experimental conditions and methods for coating fresh eggs as mentioned previously, at the same time done the contrast with the four best single extracts. From sensory and physicochemical index, we could see that all treatment group had a certain preservation effect on eggs. Compared with the bacteriostatic effect of the four best extracts used alone, the compound extracts group's sensory changes, content of dense albumen, Hough unit of compound extracts were worse, weight losing rate was better, and yolk coefficient of compound extracts have little difference with single treatment group. From comprehensive results of index, we concluded preliminarily that the inhibiting effect of single herbal plant extracts is better than the compound extracts. We judged preliminarily when there was the antagonism between each component, the bacteriostatic effect of interaction was less than the sum of single component, namely that there was antagonism between the different active antibacterial material in the four herbal plants so that reduced the bacteriostatic effect.(3) Studied on antibacterial test of single herbal plant extracts and their compounds, we obtained all extracts have bacteriostatic effect on three selected bacteria (Escherichia coil, Salmonella, Staphylococcus aureus Rosenbach) at the concentration of 0.2500 g/mL, and the higher concentration, the better the result. Meanwhile, the inhibiting effect of single herbal plant extracts was better than the compound extracts. From comprehensive comparison, we could conclude the bacteriostatic effect order of all tested extracts as Honeysuckle> Taraxacum mongolicum> Syzygium aromaticum L.> Ginkgo biloba L. extracts. And the four best extracts have a more broad-spectrum antimicrobial effect. Honeysuckle extract had a strong inhibitory effect on all bacteria, especially on staphylococcus aureus; Syzygium aromaticum L. extract showed a strong bacteriostatic effect on E.coli; Taraxacum mongolicum extract had a stronger inhibiting effect on Salmonella than staphylococcus aureus and E. coli, but it isn't suitable for eggs fresh-keeping when the extract at more than 0.5000 g/mL with a pungent smell. Honeysuckle, Syzygium aromaticum L. and Ginkgo biloba L. extracts are hence suitable for food preservation indeed.