Antibacterial Properties of Starch Blending with Glycidyl Trimethyl Ammonium Chloride and Potassium Sorbate Used in Medical Dressings

Starch is easy to breed bacteria,which affects its performance and application in medical dressings.In this research,antibacterial starch was prepared by physical blending method with glycidyl trimethyl ammonium chloride(GTA)and potassium sorbate as antibacterial agents.The antibacterial activities of GTA,potassium sorbate,GTA-starch and potassium sorbate-starch were investigated with the purpose of understanding the growth of bacteria in starch system.Results showed that GTA had good antibacterial activity,and the bacteriostasis rate of 0.05 g/mL GTA against Staphylococcus aureus(S.aureus)was 96.55%.The antibacterial properties of starch increased with an increase of mass fraction of potassium sorbate and then decreased with the continuously increasing of mass fraction of GTA.GTA-starch with30%GTA showed the best antibacterial activities,the bacteriostasis rate of Escherichia coli(E.coli)and S.aureus were 26.48%and20.26%,respectively;50%potassium sorbate in potassium sorbatestarch showed the best antibacterial activities,the bacteriostasis rate of E.coli and S.aureus were 67.68%and 74.75%,respectively.

Development of Chitosan Film Incorporating Garlic Oil or Potassium Sorbate as an Antifungal Agent for Garlic Bread

Chitosan is a biopolymer material. Mechanical, physical and barrier properties of different chitosan films incorporating garlic oil at 25, 50 and 100 μL/g chitosan or potassium sorbate at 25, 50 and 100 mg/g chitosan as antifungal agents were studied. Addition of garlic oil or potassium sorbate into the films did not alter their color except at the highest concentration of garlic oil which resulted in a more yellowish film. Garlic oil reduced film strength and elongation but it had no effect on water vapor transmission rate. Potassium sorbate reduced film strength and water vapor transmission rate, but it increased oxygen transmission rate. Films containing garlic oil or potassium sorbate was used to wrap around garlic bread to evaluate its shelf life. The development of mold on the bread surface was observed daily. The results showed that garlic bread wrapped in chitosan film incorporating garlic oil had 23 days shelf life, compared with only 7 days shelf life of garlic bread without wrapping. Garlic bread wrapped by film containing potassium sorbate had 13 days shelf life. Garlic breads wrapped by the films incorporating either garlic oil or potassium sorbate were acceptable in terms of sensory evaluation.

Diffusion Analysis and Modeling of Potassium Sorbate in Gelatin Based Antimicrobial Film

The diffusion of potassium sorbate incorporated into gelatin based antimicrobial film was measured. Fick’s second law was applied to investigate the mechanism of potassium sorbate released from the films. The mathematical model was established. The result showed that the diffusion coefficient D increased with the increase of potassium sorbate concentration. The effects of temperature 5?C, 25?C and 35?C on diffusion were investigated. The mechanisms of potassium sorbate diffusion through gelatin films were mainly Fickian and determined by the power law model Mt/M∞ = k × tn. A decrease in temperature from 35?C to 5?C resulted in a reduction of diffusion coefficients from 5.20 × 10?12 to 1.36 × 10?12 m2/s. The diffusion coefficient of potassium sorbate is influenced by receiving solution pH values.

Study on Preservative Formula and Shelf Life of Cantonese Style Moon Cakes

To ensure the safety of consumers, prolong the shelf life of moon cake and reduce the cost of manufacturing and marketing enterprises, the optimization of preservative formula and the shelf life of cantonese style moon cake were studied. Through single and compound formula preservative test, the results showed that potassium sorbate and sodium dehydroacetate could inhibit the microorganisms in the moon cake, but the inhibitory effect of sodium dehydroacetate was stronger than that of potassium sorbate; and the combination of potassium sorbate and sodium dehydroacetate had a synergistic effect, and the best formula is ＇potassium sorbate 0.44 g/kg mixed with sodium dehydroacetate 0.38 g/kg. A batch of moon cake was prepared with the best preservative formula, then the total number of colonies, molds and coliform group in the samples were detected by random sampling at irregular intervals. The total number of molds exceeded the limit on the 187^th d, and it indicated that the shelf life of the product was 187 d. Compared with the conventional 15-day shelf life, this research greatly prolongs the sheff life of cantonese style moon cake, and cut down the cost of moon cake enterprises. It is worthy of popularization and application.

Application of Hyperspectral Imaging Technology in Rapid Detection of Preservative in Milk

To ensure the quality and safety of pure milk,detection method of typical preservative-potassium sorbate in milk was researched in this paper.Hyperspectral imaging technology was applied to realize rapid detection.Influence factors for hyperspectral data collection for milk samples were firstly researched,including height of sample,bottom color and sample filled up container or not.Pretreatment methods and variable selection algorithms were applied into original spectral data.Rapid detection models were built based on support vector machine method(SVM).Finally,standard normalized variable(SNV)-competitive adaptive reweighted sampling(CARS)and SVM model was chosen in this paper.The accuracies of calibration set and testing set were 0.97 and 0.97,respectively.Kappa coefficient of the model was 0.93.It could be seen that hyperspectral imaging technology could be used to detect for potassium sorbate in milk.Meanwhile,it also provided methodological supports for the rapid detection of other preservatives in milk.

Global Solution for Preserving Citrus Fruit Using Natural Treatments

Different tests were carried out to assess the efficiency of replacing plant protection products used at the main application points in citrus fruit packinghouses with natural treatments. The efficiency of an aqueous treatment containing potassium sorbate was found to significantly reduce decaying in Marisol mandarins previously inoculated with Penicillium digitatum and Penicillium italicum. The same food preservative was used in conjunction with a fruit detergent and was applied on Washington Navel oranges and the reduction in the appearance of decaying was similar to that obtained using Guazatine. Finally, two different essential oils were tested. One was combined with a coating and the KS, whilst the other was applied as a fumigant. In the case of wax treatments, it was found that the combination of essential oil or KS with Imazalil at half the dose （0.1%） was equivalent to treatment with a higher dose of Imazalil （0.2%） thus making it possible to reduce the dose of plant protection products used without reducing decay control effectiveness. The treatment with a fumigant with essential oil has a level of efficiency similar to Imazalil against PI. These treatments can be considered a viable alternative to the use of plant protection products.

Stability study of fortified low-fat spreads with preservatives

Physicochemical variations in products are known to occur depending on storage conditions.This study examined the effects of storage time on the physicochemical,sensory,rheological,and microbiological properties of fortified low-fat spreads.Fortified spreads containing potassium sorbate(PS;0.05%and 0.1%)or MicroGard 100(MG;0.5%and 1%)as preservatives and a control spread(CS)were packed in presterilized airtight polyethylene jars and their shelf lives were investigated by storage at(5±1)℃for 91 d.Based on the physicochemical properties,the addition of preservatives inhibited the formation of free fatty acids and thiobarbituric acid and influenced the pH and acidity.The emulsion stability of the preserved samples was greater than that of the CS after 14 d.As storage progressed,the sensory and rheological properties of the CS deteriorated continuously,whereas significantly smaller changes were observed for the samples containing 0.1%PS and 1%MG.The surface growth of yeasts and molds was the main cause of spoilage,particularly in the CS.For all the samples,the standard plate counts and the yeast and mold counts increased during storage.In contrast,the coliform counts were zero,indicating that the samples were manufactured and stored under hygienic conditions.The samples containing lower levels of preservatives(0.05%PS and 0.5%MG)were acceptable for 70 d and 77 d as compared to 49 d for the CS.Notably,the addition of 0.1%PS and 1%MG extended the shelf life to 91 d.