Fatty acid content and chemical composition of vegetative parts of perilla (Perilla frutescens L.) after different growth lengths

Perilla (Perilla frutescens L.) belonging to the Lamiaceae family, is an edible plant that is frequently used as one of the most popular garnishes and food colorants in some Asian countries and as part of popular and traditional Chinese herbal medicines. The objective of this study was to determine the fatty acid (FA) content, chemical composition and gross energy (GE) of the plant during the growth cycle. Herbage samples were collected four times at progressive morphological stages from 15 cm to 70 cm of plant height. The FA profiles in the plant were characterised by three dominant FAs: palmitic acid (C16:0), linoleic acid (C18:2 n-6), and ?-linolenic acid (C18:3 n-3), which ranged from 8.5-9.7 %, 11.5-12.1 %, and 52.0-55.5 % of the total FA, respectively. The FA pattern in the whole plant during growth only differed for palmitoleic acid (C16:1) and stearic acid (C18:0). The evolution of the whole perilla plant quality during growth was characterised by a progressive increase in the neutral and acid detergent fibre contents, while the crude protein content decreased from the first month after sowing to the last stage. Organic matter and GE were higher at the last stage than at the other stages. The first summer cut of perilla, whose fat fraction is rich in polyunsaturated fatty acids, should be harvested at around two months after sowing, since its nutritional quality deteriorates when cutting is delayed. Further studies are necessary to determine the changes in the other chemical constituents of perilla plant during the growth cycle.