The Impact Of Packaging Materials On The Antioxidant Phytochemical Stability Of Acqueous Infusitons Of Green Tea (Camellia Sinensis )And Yaupon Holly (Ilex Vomitoria) During Cold Storage

Ready to drink (RTD) teas are a growing segment in the beverage category, brought about by improvements in the flavour of these products and healthy market trends driven by consumers. The stability of antioxidant phytochemicals in RTD teas, namely, aqueous infusions of traditional green tea ( Camellia sinensis ) and yaupon holly ( Ilex vomitoria ) as influenced by their packaging during cold storage was investigated. Each tea was packaged in glass or PET, packaging materials used commonly for RTD products, or in a retort pouch, an emerging packaging material for various types of food since it is durable, inexpensive, lightweight and easy to sterilize. Stability was evaluated for each aqueous infusion (prepared with a concn. of plant material of 10 g/l at 90(deg)C for 10 min) stored at 3(deg)C in the absence of light for 12 wk. Analyses included quantification and characterization of individual polyphenols using HPLC-photodiode array and LC-electrospray ionization-MS as well as changes in total antioxidative capacity. For green tea, concn. of the 3 major flavan-3-ols, epigallocatechin gallate, epigallocatechin, and epicatechin gallate were better retained in glass bottles as compared with retention in either of the other packs during the 12 wk storage period. For the herb tea, chlorogenic acid and its isomers were the predominant compounds and were generally stable irrespective of the packaging material, a 20.6-fold higher concn. of saponin was found compared with that in the green tea, and it is suggested that this caused higher stability of flavonol glycosides in the herb tea during storage. The antioxidative capacity of green tea was better retained in the glass and PET containers than in the retort pouch, whereas no effect of packaging on antioxidative activity retention during storage of the herb tea was found. Results highlight the superiority of O SUB 2 -impervious glass packaging, but show that viable alternatives may be utilizable for RTD teas with variable phytochemical compositions.