john5r: (Default)
[personal profile] john5r
В продолжение давно волновавшей меня темы почему в холодильнике "лучше пропитывается".

Вот сделал вчера рыбу под маринадом. Ее в рецепте, естественно, рекомендуют поставить в холодное место на подольше, чтобы пропиталась. А при комнатной температуре не пропитается? Но, положим, пропитка не зависит от температуры, а вкус - зависит? Зависит. А почему он зависит?
Daily experience tells us that temperature has a strong influence on how we taste. Despite the longstanding interest of many specialists in this aspect of taste, we are only starting to understand the molecular mechanisms underlying the temperature dependence of different taste modalities. Recent research has led to the identification of some strong thermosensitive molecules in the taste transduction pathway. The cold activation of the epithelial Na(+) channel and the heat activation of the taste variant of the vanilloid receptor (TRPV1t) may underlie the temperature dependence of salt responses. Heat activation of the transient receptor potential channel TRPM5 explains the enhancement of sweet taste perception by warm temperatures. Current development of methods to study taste cell physiology will help to determine the contribution of other temperature-sensitive events in the taste transduction pathways. Vice versa, the analysis of the thermodynamic properties of these events may assist to unveil the nature of several taste processes.

Отрывок из публикации 2007 года. "...мы только начинаем понимать молекулярный механизм, стоящий за зависимостью разных вкусов от температуры. Недавние исследования позволили выявить очень термочувствительные молекулы в цепи переноса вкусового сигнала. Активизация эпителиальных натриевых каналов при холоде и ваниллоидных рецепторов (TRPV1t) при тепле могут быть связаны с зависимостью реакции на соленое от температуры. Активизация при тепле избирательных ко вкусу катионных каналов TRPM5 объясняет усиление сладкого вкуса при повышении температуры."
TRPM5, a cation channel of the TRP superfamily, is highly expressed in taste buds of the tongue, where it has a key role in the perception of sweet, umami and bitter tastes. Activation of TRPM5 occurs downstream of the activation of G-protein-coupled taste receptors and is proposed to generate a depolarizing potential in the taste receptor cells. Factors that modulate TRPM5 activity are therefore expected to influence taste. Here we show that TRPM5 is a highly temperature-sensitive, heat-activated channel: inward TRPM5 currents increase steeply at temperatures between 15 and 35 degrees C. TRPM4, a close homologue of TRPM5, shows similar temperature sensitivity. Heat activation is due to a temperature-dependent shift of the activation curve, in analogy to other thermosensitive TRP channels. Moreover, we show that increasing temperature between 15 and 35 degrees C markedly enhances the gustatory nerve response to sweet compounds in wild-type but not in Trpm5 knockout mice. The strong temperature sensitivity of TRPM5 may underlie known effects of temperature on perceived taste in humans, including enhanced sweetness perception at high temperatures and 'thermal taste', the phenomenon whereby heating or cooling of the tongue evoke sensations of taste in the absence of tastants.

И из 2005 года
"TRPM5, катионный канал семейства TRP, активно экспрессируется во вкусовых сосочках языка и играет в них главную роль в восприятии сладкого, горького и пряного вкусов. ... TRPM5 активируется под воздействием тепла и обладает высокой чувствительностью к температуре: входящий ток в канале TRPM5 резко возрастает в диапазоне от 15 до 35 градусов Цельсия."

Anonymous( )Anonymous This account has disabled anonymous posting.
OpenID( )OpenID You can comment on this post while signed in with an account from many other sites, once you have confirmed your email address. Sign in using OpenID.
Account name:
If you don't have an account you can create one now.
HTML doesn't work in the subject.


Notice: This account is set to log the IP addresses of everyone who comments.
Links will be displayed as unclickable URLs to help prevent spam.

May 2015

17 181920212223

Most Popular Tags

Style Credit

Expand Cut Tags

No cut tags
Page generated Sep. 25th, 2017 10:13 pm
Powered by Dreamwidth Studios