Effect of rainfall and altitude on the 2‐acetyl‐1‐pyrroline and volatile compounds profile of black glutinous rice (Thai upland rice)

Abstract

BACKGROUND: The aroma intensity of rice is mixed of more than 100 volatile compounds. Fragrant rice is famous in Thailand due to specific aroma. One important volatile compound that contributes to aromatic intensity and represents a characteristic compound for fragrant rice is 2-acetyl-1-pyrroline (2AP). The production of volatile compounds and 2AP in rice is affected by various environmental factors, such as cultivation area, water content and temperature.RESULTS: Our research employed 29 samples of fragrant colored rice (Luempua black glutinous rice cultivar) from Phetchabun province, Thailand from three harvested rice seasons (2015)(2016)(2017). The cultivation areas of rice samples exhibited differences in rainfall (976.6-1260.5 mm y r −1 ) and altitude (26.26-1033.41 m). All volatile compounds and 2AP were identified by gas chromatography-mass spectrometry (GC-MS). In 29 rice samples, 2AP levels decreased with increasing of rainfall. The increase in altitude seems to increase 2AP levels, but some high-altitude cultivation areas resulted in low 2AP content. A variety of volatile compounds was observed in 29 rice samples from different cultivation areas. The results showed that differences in altitude and rainfall affected the production of volatile compounds in fragrant colored rice. Moreover, our results indicated that different environmental conditions in cultivation areas potentially affect volatile compound production during rice growth. CONCLUSION:The increase in 2AP levels under low rainfall conditions and the assortment of volatile compound varieties produced in colored rice grown in different cultivation areas may be useful information for rice cultivation management striving to produce rice with high aromatic intensities.

Aroma Compounds Are Responsible for an Herbaceous Off-Flavor in the Sweet Cherry (Prunus avium L.) cv. Regina during Fruit Development

“…These researchers associated altitude with temperature, where the differences in the aroma profile were determined by the minimum air temperatures at night. In another study, the rainfall and altitude affected the production of 2-acetyl-1-pyrroline (2AP), an important aroma constituent of a fragrant colored rice [55]. In their study with 29 samples of rice under different rain regimes and altitude ranges (26.26 to 1033.41 m above sea level), 2AP decreased with increasing rainfall, and those samples harvested from higher altitudes presented higher 2AP content than those from lower altitudes.…”

Multi-omics analysis reveals the genetic basis of rice fragrance mediated by betaine aldehyde dehydrogenase 2

“…The accessions with Hap_2 carrying badh2-E10-4488C > A causing an alanine to glutamic acid substitution [42] and Hap_4 characterized by a synonymous SNP ( badh2-E10-4528G > A ) [15] , [44] did not show 2AP accumulation. Such variation in 2AP accumulation in fragrant rice can be attributed to environmental factors and variation in cultivation practices [58] , [59] , however differences in the levels of transcripts with similar coding sequences also significantly influence plant phenotypes [60] , [61] .…”

Inhibition potential of volatile compounds from Thai rice cultivars against acetylcholinesterase through in vitro and docking studies

“…Vanillin and guaiacol have been reported as the volatile compounds mixed for rice aroma intensity (Hinge et al, 2016; Sansenya & Wechakorn, 2021). Methyl vanillate is the derivative of vanillic acid and is found in some plant species as well as in rice (Suttiarporn et al, 2016).…”