## 1 Introduction  
Sacha inchi (_Plukenetia volubilis_ Linneo), from the Euphoriaceae family, also known as inca peanut, wild peanut, or sacha peanut, is generally cultivated in many regions of the Peruvian Amazon [1]. Sacha inchi has significant potential economic value in cosmetic, pharmaceutical, and food industries, and has recently been introduced as an alternative crop in Thailand. In 2020, the global Sacha Inchi market volume was valued at 92 Million USD in 2020. However, it is expected to receive a higher market share with a CAGR of 4.7% to reach 125.8 million USD during 2021-2027 [2]. The increasing demand for vegan, organic products, protein-rich food products, and supplements, as well as its demand in the food and beverages industry and the cosmetics sector, is expected to push the sacha inchi industry growth [3]. At present, several commercial products have increased availability in particular oil, roasted seeds, and protein powder or flour. Sacha inchi seeds are nutritionally superior as a good source of oil (-41%), protein (-27%), and bioactive compounds [4], such as polyphenolic compounds, phytosterols (stigmasterrol and campesterrol), and tocopherels. The oil is rich in unsaturated fatty acids (-93% of total lipids). Essential fatty acids in the seeds comprise 33% \(\alpha\)-linoleic acid and -51% \(\alpha\)-linolenic acid [5]. The seeds contain high amounts of essential amino acids, such as isoleucine, valine, and tryptophan [6]. However, they also contain antimutritional components, such as saponins, tannins, and trypsin inhibitors [7, 8], and are usually consumedroasted because of the astringency due to antinutritional components. The germination conditions of sacha inchi could reduce tannins and other antinutritional components and enhance the seeds' nutritional quality [9]. Germination has been studied in many seed plants, such as soybean [10], barley [11], mung bean [12], sunflower [13], and mangosteen [14]. A germinating seed depends on reserve carbohydrates, proteins, and lipids synthesized and stored during seed growth. These compounds are synthesized during germination via glycolysis, the tricarboxylic acid (TCA) cycle, and amino acid metabolic pathways. Germination begins with water imbibition, food reserve mobilization, protein synthesis, and consequent radicle protrusion--the main food reserve for seedling development. The food reserves may be stored mainly in the endosperm (many monocotyledons, cereal grains, and castor) or cotyledons (many dicotyledons, such as peas and beans). The macronutrients (proteins, lipids, and carbohydrates) are enzymatically (amylases, proteases) hydrolyzed into simple units of food comprising sugars and amino acids. These dissolve in water and pass toward the growing epicotyl, hypocotyl, radicle, and plumule through the cotyledons [15]. Triacylglycerglycerol (storage lipids) metabolism during germination has also been reported in sacha inchi. During germination, triacylglycereeds are hydrolyzed into fatty acids by lipase via lipid metabolism. The released fatty acids undergo \(\beta\)-oxidation to generate adenosine triphosphate (ATP) as the major energy supply within the seeds [16]. However, germination time is positively correlated to off-flavor in germinated seeds. The activity of lipoxygenases (LOXs) on storage lipids in seeds can produce oxidation products, such as aldehydes and alcohols, leading to unpleasant beauty, green, or rancid flavors [17]. The metabolites and flavor compounds that change during germination can be used as biomarkers according to the germination stages in sacha inchi. Metabolomics is the scientific study of multiple small molecules in cells, tissues, plants, or foods. The metabolite profile contains valuable data for breeding-driven metabolic engineering of nutritionally important metabolites in plants. Metabolomics has been applied in plant and food science to study the effect of germination on mung bean [12] and barley [11] and the effect of processing and storage on Nam Dok Mai mango wine fermentation [18].