Introduction, Objectives: The polymeric gel-forming mucins provide together with other proteins the structural framework of saliva and the mucus barriers that cover the mucosal surfaces of the oral cavity. The polyphenols content in green tea, which have many health benefits, are able however influence the barrier properties of these protective layers. The aim of this study it is that to verify in vitro such effects on two different samples of saliva Materials Methods: In two male volunteers, asked to provide a saliva sample, obtained from the collection of the same, at various times of the day, they were determined the pH, density, total proteins and mucins. To these samples they have been assistant increasing quantities of extract of green tea, and then, after centrifugation, determined in the surnatant the concentrations of total proteins and total mucins. The results are analyzed with Fisher Exact Test and T –Test Results: The precipitation of proteins and mucins in both samples after the addition of green tea extract are not statistically non-correlated data (p≥0.05), to the increase the amount of polyphenols compounds, but points out a tendency, by the Fisher Exact Test (FET). The results of this trend arising for the sample 1 by the maximum proteins precipitation value of 32,% and 57.6 %, for the mucins. Test 2 maximum precipitation for the proteins is 28.5%, and 50.0% for mucins. From the same results it is underlined instead that in both the champions the differences of concentration between the mucins and the proteins are statistically significant: the difference of the medium vale with T-TEST is ≥ 0 for both samples Discussion: The two samples of saliva have different initial biochemical parameters values; this fact influence in the differences in the precipitation of the proteins in the two different champions, as it happens for the mucins, but, also the different behaviour between the same proteins and mucins to parity of green tea assistant extract. A value of more elevated, or more distant pH from the isoelettric point, it stretches the protein structures favouring the interaction of the same with the polyphenols, The mucins are in this case more receptive for the presence of polysaccharide terminals groups Conclusions: These data demonstrate the possible effect of a dietary using of the green tea on the mucin network; given the diversity of human diet, many other dietary compounds may also affect the properties of mucus barriers at the level of the mucin network, but the polyphenols compounds are the most important in the alteration of mucus barrier properties in health and disease states, as demonstrated from this study and from various epidemiological evidence