# Biochemical and gene expression analyses character volatile compounds, fatty acids, and physiochemical properties of Stauntonia obovatifoliola seed oil

## TL;DR

This study explores the seed oil of Stauntonia obovatifoliola, revealing high carotenoids, unsaturated fatty acids, and 28 volatile compounds, with potential applications in food and cosmetics.

## Contribution

First systematic evaluation of S. obovatifoliola seed oil's biochemical and gene expression profiles.

## Key findings

- Seed oil contains high carotenoids (77.49 mg/100g) and unsaturated fatty acids (66.68%).
- 28 volatile compounds, including terpenes and alkanes, were identified using HS-SPME-GC–MS.
- Gene expression suggests substrate competition between carotenoid and fatty acid synthesis.

## Abstract

Stauntonia obovatifoliola subsp. urophylla is a promising oilseed crop. This study first systematically evaluated its seed oil including physicochemical properties, fatty acid profile, and volatile compounds, and genes related to carotenoid and fatty acid biosynthesis. The oil had high carotenoid content (77.49 ± 1.11 mg/100 g), moderate iodine value (82.91 ± 2.86 g/100 g), low acid and peroxide values, and antioxidant/antimicrobial activities. Mature seeds contained unsaturated fatty acids (UFAs, 66.68 %), mainly oleic acid (30.93 %) and linoleic acid (21.00 %). A distinctive C19:1N9T component was also detected. Twenty-eight volatile compounds including eight terpenes, eight alkanes, five alcohols, five arenes and two aldehydes. Notably, during rapid oil accumulation phase (July to August), fatty acid biosynthesis genes were elevated, whereas carotenoid synthesis genes were suppressed, suggesting substrate competition. These findings offer help in purposefully exploitation and utilization of S. obovatifoliola seeds oil in food, cosmetics and pharmaceuticals.

•S. obovatifoliola is a herb and an emerging fruit, as well as a oil-producing plant.•This is the first investigation into seed oil of S. obovatifoliola.•S. obovatifoliola seed oil had high level of carotenoids and unsaturated fatty acids.•HS-SPME-GC–MS analysis detected 28 volatiles in S. obovatifoliola seed oil.•There may be a substrate competition between carotenoid synthesis and lipid synthesis.

S. obovatifoliola is a herb and an emerging fruit, as well as a oil-producing plant.

This is the first investigation into seed oil of S. obovatifoliola.

S. obovatifoliola seed oil had high level of carotenoids and unsaturated fatty acids.

HS-SPME-GC–MS analysis detected 28 volatiles in S. obovatifoliola seed oil.

There may be a substrate competition between carotenoid synthesis and lipid synthesis.