'starch-rich' originates from Modern English, formed by combining the noun 'starch' and the adjective 'rich'.

'starch' changed from Middle English 'sterche' (or 'starch') and Old English 'stearc', and eventually became the modern English word 'starch'; 'rich' comes from Old English 'rice' meaning powerful or abundant and developed into Modern English 'rich'.

Initially, Old English 'stearc' meant 'stiff' or 'strong'; over time the word came to denote the substance (starch) that stiffens cloth and then the modern sense of the carbohydrate 'starch'. Combined as 'starch-rich', the phrase now means 'abundant in starch'.