Yes, soya is a Scrabble word!

Noun

1. Erect bushy hairy annual herb having trifoliate leaves and purple to pink flowers; extensively cultivated for food and forage and soil improvement but especially for its nutritious oil-rich seeds; native to Asia

2. The most highly proteinaceous vegetable known; the fruit of the soybean plant is used in a variety of foods and as fodder (especially as a replacement for animal protein)