The Studies On The Moulds And It's Inhibition In Bakery Products

The bakery products are rich in nutrition.Not only they are easily oxidized and go bad,but also more easily spoilaged by moulds. Moulds can cause significant economic losses,and some moulds can produce toxic secondary metabolites(mycotoxins),which can affect human health.Using preservative to inhibit moulds is very important for maintaining the safety and nutrition of the bakery food. As chemical preservative usually faces safety trouble, natural preservative is getting more popular. Therefore, this paper has studied the moulds inhibition effect provided by the cinnamon and clove essential oils on the basis of bakery-food moulds'separation and purification, aiming to provide some information on using essential oil to preserve bakery food theoretically and practically.First of all, 6 strains of moulds marked A, B, C, D, E and F were separated and purified from the spoilaged bakery food. According to the single colony's two-side modality and color, and microscope observation results on spore and mycelium's morphological characteristic, and mycelium's growth characteristic by moist chamber culture, A was identified as Penicilluma,D was Mucor while B,C,E,F were Aspergillu.Next, the inhibition effect of the natural cinnamon and clove essential oils for the six moulds were studied. The original moulds density was controlled at about 106cfu/ml in experiments. Using gas/solid diffuse bacteriostatic methods respectively to investigate the inhibition effect of the essential oils with different concentration for the six moulds strains, a good linear positive relation between the essential oils'used concentration and the bacteriostatic ring (R>0.9) was found. Besides, the MIC and MLC of the the six moulds strains were examined by double-dilution method. Under adding 1.2μl/dish essential oil condition, the bacteriostatic ring diameter of the strain A-F were 68.0±0.2, 63.0±0.1, 74.5±0.2, 11.3±0.3, 41.7±0.06 and 55.0±0.05mm respectively for the cinnamon essential oil, and for the clove essential oil, the bacteriostatic ring diameter of the strain A and C were 23.1±0.2 and 12.6±0.3mm respectively, but all the rest 4 strains showed no obvious bacteriostatic rings. Thus, the moulds inhibition effect of the cinnamon essential oil was better than the clove essential oil. Besides, comparing with other 5 strains, strain D showed the least sensitivity to the two essential oils'inhibition,and A,C were more sensitive than others.Finally, the two essential oils were applied in bread with dried meat floss, green bean cake and finger citron crisp cake as preservatives. Following the original processing technics, smear way and point way were used to add the essential oils, and the sensory test results showed that there was a distinct difference at 1% level between the samples adding essential oils by smear way and the control sample, but no distinct difference at the same level was found between the samples adding essential oils by point way and the control sample. Becides, the samples adding essential oils by point way were packed in directly sealed bags (ordinary package) and vacuum packages respectively, followed by accelerative storage at 30℃, and the results showed the ordinary package could prolong the shelf life of the bakery food by 2 to 10 days while the vacuum package could help to prolong by about 15 days.