Why so Gritty?

People either love pears or hate them. Much depends on the kind of pear. Those who would rather have any other available fruit find pears to have an unappealing gritty texture. Why is that?

If pears seem gritty, it’s because they are essentially filled with grit. Specialized clusters of cells called “sclereids” or “stone cells” are scattered throughout a pear’s flesh. Stone cells are structural cells with heavily lignified walls. If you’re wondering what “lignified” means, lignin is a complex organic polymer that is a primary component of wood. As a stone cell develops, its walls continue to thicken and its insides fill with lignin until it becomes a solid little chunk. Surrounding cells also thicken and eventually form aggregates or clusters. Needless to say, in the process of becoming a solid wooden nugget, stone cells end up stone dead.

Pear flesh isn’t the only place you can find sclereids. They come in all kinds of shapes and sizes. They are present in the vasculature of plants, bark, stems, roots, seed coats and the shells of nuts. So if you find that the experience of eating a pear is akin to chewing hundreds of microscopic walnuts in a mildly sweet fruit paste, you would ’t be too far from the truth.

Brian Rutter, PhD, is the cofounder of Thing in a Pot Productions and a postdoctoral researcher in plant biology at Indiana University. Subscribe to our newsletter to receive our “Things About Things – Odd Facts About Plants” and video production tips in your inbox every month!

Works Cited:

Cheng, X., Cai, Y., & Zhang, J. (2019). Stone Cell Development in Pear. The Pear Genome, 201-225.