Characteristics of Korean rice varieties and their potential end-uses

As Korean consumers are increasingly attracted by Western foods and more and more abandoning their conventional diets, the Rural Development Administration (RDA) of the Korean National Institute of Crop Science is involved in enhancing and developing alternative rice-based foods, presently uncommon on the Korean market. Traditionally, in Oriental countries milled rice is consumed after boiling in water and combined with other courses. Therefore, to vitalize this sector, the RDA is planning the production of added-value foods, such as dried pasta and “risotto”, two well-known Italian-style products. Rice from four Korean O. sativa varieties (two subsp. japonica – Dodamssad and Mylang 344 - and two subsp. indica – Saemimyeon and Shingil) were characterized and compared to four Italian varieties, all from subsp. japonica (Carnaroli, Volano, Vialone Nano –indicated for risotto preparation - and one subsp. tropical japonica – Gladio - preferred for the parboiling process). Besides the characteristics of the starch fraction (amylose content, alkali test, pasting properties), the cooking behavior (i.e. rice hardness and stickiness) were considered. The three Italian cvs recommended for risotto belong to different commercial classes according to their biometric characteristics and their amylose content (Italian law n. 131/2017). Nevertheless, they are all characterized by a long gelatinization time (16-17 min), a high alkali index (5-7) and a good texture after cooking (i.e. surface stickiness as well as good grain consistency). Among the Korean varieties, Saemimyeon cv results in the best risotto, even if its alkali test value is very low and its grain hardness is quite high, traits indicating low starch swelling during cooking. Concerning rice-pasta production, the literature suggests that high amylose (> 25%) varieties are preferable as they are more suitable in forming a strong and regular starch network during the thermal treatments carried out during the extrusion process. With the exception of Dodamssad cv, whose amylose content (41.7%) is too high to obtain (according to its pasting property indications) sufficient granule swelling, Saemimyeon and Shingil cvs seem to have the right traits for assuring good results in rice-pasta processing. In conclusion, none of the Korean rice varieties tested so far seem to guarantee a cooking performance during risotto preparation similar to that observed using Italian varieties. On the contrary, the former exhibit promising characteristics for rice pasta-making. Further investigations will focus on starch digestibility, which might be strongly affected by the amylose content and may lower the Glycemic Index of the cooked product.