| Tea(Camellia sinensis(L.)Kuntze)flower,the reproductive organ of tea plant,contains representative metabolites similar to those of tea leaves,such as catechins,flavonols,caffeine,and amino acids.Tea flower was used as a food garnish to form foam in Japanese-style dishes in ancient Japan,and have been incorporated into a range of drinks in India.Tea tree flower has the effects of scavenging free radicals,anti-proliferation and anti-obesity,in the meanwhile,tea flower has no side effects and should be of no toxicological concern in daily life.Which have attracted the attention of researchers for the content of functional compounds and medicinal effects in recent years.As a new food resource,tea tree flower has good development prospects.However,tea tree flowers have a strong and persistent bitterness that is different from tea leaves,especially tea tree petals.This greatly limits the use of tea tree flowers in the food industry.Tea tree pollen is rich in nutritional and functional ingredients,such as amino acids,proteins,tea polyphenols,tea polysaccharides,peroxide dismutase,catalase,caffeine,vitamins,trace elements,etc Its antioxidant properties are comparable to rosemary.At the same time,it has the functions of detoxification,bacteriostasis,hypoglycemic,anti-aging,anti-cancer and anti-cancer,and enhance immunity.These functions will greatly expand the application and development space of tea tree flowers.In addition,tea tree pollen also contains theanine(0.54%?1.02%)that is not found in other pollen.Theanine is a safe active ingredient that has decompression,improves cognition,regulates mood and lowers blood pressure.Breaking the pollen cell wall can release pollen nutrients,making it easy for the body to absorb and useIn this paper,tea flower is taken as the research object.By measuring the change of quality components of tea tree pollen before and after breaking the cell wall disruption,and combining sensory evaluation and antioxidant capacity evaluation methods,the effect of different wall breaking methods on the quality of tea tree pollen is analyzed;the substances in tea petals were identified by liquid chromatography spectrometer and multivariate statistical method.This paper aims to provide reference for the development and utilization of tea flower resources.The main research contents and achievements are as follows1.The tea flower petals contained catechins ranging from 30.23mg/g to 50.72mg/g,and the main groups were GC,C,EC and EGCG.Caffeine is the dominant alkaloid in the petals of tea tree,and its content varies from 1.89mg/g to 4.94mg/g,which is generally lower than that of tea leaves2.Vacuum freeze-dried tea tree pollen was used as the experimental material,the superfine grinding,freeze-thaw method,and enzymatic hydrolysis-ultrasonic combined treatment were used to break the cell wall of the tea tree pollen.The change of pollen functional active substance before and after wall breaking is closely related to the way of wall breaking.The nutrient release of wall-breaking pollen showed an increasing trend compared with non-wall breaking pollen.After wall-breaking,the release of phenolic compounds,flavonoids,proteins,amino acids,and reducing sugars increased.The particle size can reflect the situation of pollen wall fragmentation.The smaller the particle size,the more serious the pollen destruction,and the more obvious the wall breaking effect.From large to small,the pollen particle size was freeze-thaw method,combination of enzymatic hydrolysis and ultrasonication method,and superfine grinding method.superfine grinding can maximize the sample's wall breaking rate,followed by combination of enzymatic hydrolysis and ultrasonication method,and freeze-thaw method.3.Optimize the combination of enzymatic hydrolysis and ultrasonication wall breaking process,and examine the effects of three factors:material-liquid ratio,temperature,and treatment time on pollen wall-breaking rate.The optimal process parameters obtained through optimization of response surface design are:material-liquid ratio 1:22g/mL,enzymatic hydrolysis temperature 47?,processing time 5.5h.It can be seen from the response surface graph that the effect of enzymolysis temperature and action time on the wall breakage rate is the most significant.The influence of each factor is analyzed by range analysis:processing time>enzymolysis temperature>material-liquid ratio.4.The antioxidant capacity of tea tree pollen was evaluated by DPPH method and ORAC method.The results showed that both superfine grinding and ultrasonic-assisted enzymatic treatment could enhance the scavenging ability of DPPH free radicals and the ORAC value.DPPH free radical scavenging rate was significantly correlated with total polyphenols,total flavonoids,and total catechins,among which EGCG had the highest correlation.In the ORAC measurement,the wireless relationship between total polyphenols,total flavonoids and ORAC values,which is related to the complex polyvalent structure of polyphenols.In addition,the content of EC in tea tree pollen had the highest positive correlation with ORAC value.5.The sensory quality of pollen after wall-breaking treatment showed a downward trend,which was mainly manifested in three aspects:darker color,bitter taste and worse smell.The degree of pollen browning was significantly related to the activities of polyphenol oxidase(PPO)and peroxidase(POD). |
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