Development Of Natural Composite Antioxidants And Preservatives Based On Bamboo Vinegar

Owning to complex chemical components, bamboo vinegar has some excellent biologicalactivities. It has received considerable attentions for the application of bamboo vinegar.Bamboo vinegar has been applied in many fields such as agriculture, industry, medicine, foodabroad. Related research is still in its infancy in our country. Bamboo vinegar is one ofnon-poisonous and safe natural products, which has antioxidant activity and antibacterialproperty and also has synergistic antioxidant and antibacterial activity. The development ofbamboo vinegar-based in food field will have a broad horizon and bright prospect.The natural composite antioxidants and preservatives based on bamboo vinegar werestudied in this paper. Natural antioxidants with different chemical structure including phenols(tea polyphenols, rosemary), ketone (bamboo leaves flavones), polysaccharides (chitosanoligosaccharide), vitamins (β-carotene); nitrogen compound (glutathione) were mixed withbamboo vinegar, respectively. The antioxidant activity of the mixtures was investigated byexaming superoxide, hydroxyl,1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals and reducingpower. Tea polyphenols, chitosan oligosaccharide, nisin were mixed with bamboo vinegar,respectively. Gram-positive Staphylococcus aureus and Gram-negtive Escherichia coli,Pseudomonas aeruginosa and Vibrio parahaemolyticus were selected as the test bacteria ofthis research. First, the antibacterial effect of bamboo vinegar and its mixtures against fourcommon pathogens was measured by inhibitory zone. Then the minimal inhibitoryconcentrations (MIC) of bamboo vinegar, tea polyphenols, and nisin were determined,respectively.On the basis of the above results, the preservation effect of bamboo vinegar, teapolyphenols, nisin and their mixtures on Penaeus vannamei was evaluated, respectively. Thesensory quality, pH value, TVB-N value and total bacterial count were determined duringstorage. As for the salmon and beef, the pH value, TVB-N value, total bacterial count and theTBA value werer determined to evaluate the effect of the preservation of the preservatives.The main conclusions of this paper are as follows: 1. Scavenging activitys of bamboo vinegar on free radicals enhanced as the concentrationof bamboo vinegar increased. The IC50of bamboo vinegar against DPPH radicals, superoxideanion, hydroxyl radicals are13.9mg/mL,6.84mg/mL and51.8mg/mL, respectively. We alsofound that bamboo vinegar has certain reducing power. When the absorbance value reached0.4, the concentration of bamboo vinegar was80mg/mL and it almost had no chelation abilitywith metal. The antibacterial of bamboo vinegar against the test bacteria enhanced as theconcentration of bamboo vinegar increased. When the concentration was diluted to10%original concentrion, the antibacterial activity was largely reduced.2. The antioxidant activity of bamboo vinegar, the mixture of bamboo vinegar with teapolyphenol, the mixture of bamboo vinegar with glutathione and the mixture of bamboovinegar with flavanone had better antioxidant activity. The mixture of bamboo vinegar withrosemary and the mixture of bamboo vinegar and β-carotene had no change in antioxidantactivity. The mixture of bamboo vinegar with chitosan oligosaccharide had less antioxidantactivity.3. The mixtures of bamboo vinegar with tea polyphenols, nisin, chitosan oligosaccharidehad an increase of antibacterial activity against the test bactera, respectively.4. The mixture of bamboo vinegar with tea polyphenols exhibited synergetic antibacterialactivity and prolonged the shelf-life of Penaeus vannamei up to7days. The mixture ofbamboo vinegar with nisin exhibited synergetic antibacterial activity and prolonged theshelf-life of Penaeus vannamei up to6days.5. The mixture of bamboo vinegar with chitosan oligosaccharide exhibited synergeticantibacterial activity and prolonged the shelf-life of salmon up to6days. While the mixture ofbamboo vinegar with tea polyphenols did not have the effect.6.The results indicated that the mixture of bamboo vinegar with tea polyphenols, themixture of bamboo vinegar with nisin, the mixture of bamboo vinegar with tea polyphenolsand nisin all exhibited synergetic antibacterial activity and prolonged the shelf-life of beef upto14days.