Spices form the basis of food pairing in Indian cuisine

Culinary practices are influenced by climate, culture, history and geography. Molecular composition of recipes in a cuisine reveals patterns in food preferences. Indian cuisine encompasses a number of diverse sub-cuisines separated by geographies, climates and cultures. Its culinary system has a long history of health-centric dietary practices focused on disease prevention and promotion of health. We study food pairing in recipes of Indian cuisine to show that, in contrast to positive food pairing reported in some Western cuisines, Indian cuisine has a strong signature of negative food pairing; more the extent of flavor sharing between any two ingredients, lesser their co-occurrence. This feature is independent of recipe size and is not explained by ingredient category-based recipe constitution alone. Ingredient frequency emerged as the dominant factor specifying the characteristic flavor sharing pattern of the cuisine. Spices, individually and as a category, form the basis of ingredient composition in Indian cuisine. We also present a culinary evolution model which reproduces ingredient use distribution as well as negative food pairing of the cuisine. Our study provides a basis for designing novel signature recipes, healthy recipe alterations and recipe recommender systems. Introduction Culinary practices are shaped by complex interplay of culture, climate, geography and genetics (1–6). These factors influence food preferences and recipe composition, thereby altering the fabric of cuisine. Recipe composition pattern in a cuisine provides a means for investigating its gastronomic history and molecular constitution. The shift to cooked diet has been proposed to be a trigger for increased brain size in humans (7). Indian culinary system has traditionally developed dietary practices where food has nutritional as well as medicinal value (8– 10). Ayurveda, the classic medicinal system of India, proposes that food has as much therapeutic value as drugs and even uses similar processing techniques for their preparation (11, 12).