Furan fatty acid concentrations in tea infusions prepared from green, black, and herbal teas

Abstract

Furan fatty acids (FuFAs) are valuable antioxidants with highly effective radical scavenging properties which are widely distributed at low levels in food. Previous research indicated that tea is a valuable source of FuFAs. However, tea is only consumed in form of infusions. To fill this gap, we prepared infusions from different herbal, green, and black teas. Initial measurements with GC-MSMS of tea verified previous findings that 11-(3,4-dimethyl-5-penylfuran-2-yl)-undecanoic acid (11D5) was the prevalent FuFA in tea matrix. Therefore, 11D5 was quantified in tea infusions by means of UHPLC-MSMS equipment after mild alkaline hydrolysis. While herbal tea infusions were low or free of FuFAs, 11D5 was detectable in all samples of green and black tea infusions. Amounts of 11D5 were higher in green tea than in black tea. Moreover, Darjeeling tea infusions were by $30% richer in 11D5 than black and green teas from other regions. Each cup of green and black tea infusion may provide 20-60 μg 11D5, which is about 5% of the amounts found in tea samples. Spread over the day, regular tea consumption may contribute to the intake of valuable FuFAs.

Furan fatty acid amounts and their occurrence in triacylglycerols of white asparagus (Asparagus officinalis) from the German market

“…Within the D‐FuFA family, 11D5 (62%–86% of the ∑D‐FuFAs, mean 72%, median 71%) was much higher abundant than 9D5. This order in white asparagus complies with most plant matrices ranging from spinach (Kirres & Vetter, 2018; Masanetz et al, 1998), to herbs (Kirres & Vetter, 2018; Sigrist et al, 2001) and tea (Belitz et al, 2008; Mawlong et al, 2016; Romanotto et al, 2022). Only some soy bean varieties and selected plant oils (olive, corn, rapeseed, wheat germ) featured an equal or a higher share of 9D5 (Belitz et al, 2008; Boselli et al, 2000; Guth et al, 1995; Guth & Grosch, 1991; Mawlong et al, 2016; Müller et al, 2020).…”

“…Predominance of D-FuFAs was also found in other fresh samples like plants (Boselli et al, 2000;Hannemann et al, 1989;Kirres & Vetter, 2018;Masanetz et al, 1998;Romanotto et al, 2022;Sigrist et al, 2001;Wu et al, 1997) and fungi (Hannemann et al, 1989;Müller et al, 2022). With the exception of latex gained from Hevea brasiliensis, (Englert et al, 2016;Hasma & Subramaniam, 1978;Liengprayoon et al, 2011), M-FuFAs contribute only to a minor extent to the total FuFA content of fresh plants (Boselli et al, 2000;Hannemann et al, 1989;Kirres & Vetter, 2018;Masanetz et al, 1998;Romanotto et al, 2022;Sigrist et al, 2001;Wu et al, 1997).…”