| Food flavoring and preservative is two important kinds of food additive, which plays an invaluable role in improve the quality of food. But common flavoring and preservative on the market are mostly synthetic substances, which will be more or less a threat to human health and the safety limit has been controversial. With the development of human society, more and more people have more favor for natural extracts. The development trend of food additives towards more natural functional extracts. Rosaceae Rosoideae fragrant raspberry Rubus L. (Rubuspungens var.oldhamii) has a variety of biological activity. The majority of this genus be used as a traditional Chinese medicine. By extracting its essential oil, crude extracts and purified to obtain flavonoids, namely the development of Hong berry flavors and preservatives, designed to provide a broader raw material for food additives and make contributions for developing a more healthy, natural additives.By steam distillation to extract essential oil, which is yellowish (green) with transparent liquid fragrance. By GC/MS analysis showed the major component of olefins and alcohols, which is 64.97% and 22.17% of the total amount of oil respectively, and contains a small amount of alkanes, esters and ethers. Where in there is a relatively high content of 3-Methyl-3,4-divinylcyclohexene (17.66%), 3-methyl-3,4-diethenyl cyclohexene (12%), Elixene (10.48%),1-Caryophyllene (8.39%), etc.. Biological activity test results show:firstly the essential oil has good resistance to Bacillus subtilis and Staphylococcus aureus activity and anti-Aspergillus niger and Penicillium fungi but not obvious such as activity against Gram-negative bacteria resistant. Secondly the essential oil scavenging DPPH radical ability and positive control ICso values of VE were 8.83 and 9.37 mg/mL, which suggested that the essential oil antioxidant capacity is higher than the Ve. Thirdly the essential oil and arbutin on tyrosinase inhibition rate of IC50 was 0.36 and 0.54mg/mL, which showed the essential oil has a better tyrosinase inhibitory activity. Based on the above biological activity, essential oil was included by P-cyclodextrin as a food flavoring agent. While the inclusion complex thermal stability, resistance to photolysis and volatility were studied results showed that the thermal stability of inclusion complexes, anti-photolysis were all good in the inclusion. The mixture of volatile was weaker. We can draw the inclusion complex has good package and sustained release effect.Aqueous solution of essential oil extracted by steam distillation concentrated by rotary evaporation to give a crude extract, which the yield was 0.12±0.06%(FW), flavonoid content was 4.05±0.08 mg/g. The crude extract has antibacterial, antioxidant and inhibit tyrosinase activity. Screening optimum process conditions of purifiying crude extracts flavonoids was macroporous resin X-5, the adsorption time of 2 h, analytical time 20 min,30% ethanol solution to eluent, though it to give flavonoids preliminary purification, which the yield was 13.56±0.14%, flavonoid content was100.00±0.15 mg/g. The purification was subjected to biological activity assay showed that:Compared with the crude extract, the purification improved antibacterial activity of Bacillus subtilis and Staphylococcus aureus but Escherichia coli and mold suppression were weaker or disappear. Preliminary purification of DPPH scavenging and tyrosinase inhibition rate increased. In view of this, the preliminary purification was able as food preservative, and verify its effectiveness. Formulated 0.625,0.312 mg/mL of preservative concentration treating fresh potato chips, after 48 h potato chips treatment with these two concentrations is still bright in comparison, no mildew cases, even better than the 10 mg/mL positive control Vc processing. The greater the concentration of preservative the better fresh berry. The preservative on tofu and fresh meat also has a certain effect.To explore functional components which plays a major preservative effect. Different polarity solvent extracted crude extracts and got higher activity with ethyl acetate, followed by silica gel column chromatography, gel layer analysis, used Bruker AVANCE-400 NMR Spectrometer respectively hydrogen nuclear magnetic resonance spectrum (1HNMR), carbon nuclear magnetic resonance spectrum (13CNMR) analysis, and comparison with the literature obtined compounds A and B. A was salicylic acid, B was unknown. Biological activity assay also showed good antibacterial and antioxidant activity. |
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