Effect of different cooking methods on loss of iron and zinc micronutrients in fortified and non-fortified rice

Abstract

Malnutrition is considered as major public health concern and is emerging challenge to food and nutrition security particularly in developing countries. Rice is the staple food and consumed by the half of the world's population which is the source of daily requirement of the nutrients. Attempts are being made to fortify rice with micronutrients, but the loss or retention of these micronutrients in different cooking methods is not well studied and documented especially in fortified rice. In the present study, paddy seeds of six Indian varieties were fortified with iron and zinc by parboiling process. Consequently, fortified polished rice had higher micronutrient contents (Fe, 106.31 ± 12.56; Zn, 97.72 ± 9.75) than non-fortified polished rice (Fe, 7.44 ± 1.05; Zn, 14.74 ± 2.94) expressed in ppm. Polished rice of both fortified and non-fortified were cooked under five different cooking conditions and analyzed for remaining iron and zinc content. Cooking rice in rice cooker without prior washing (NRC) retained highest concentration of Fe and Zinc in both fortified and non-fortified rice varieties. It also showed that fortified rice suffered higher percentage loss of micronutrient, than the non-fortified rice. But the average retained micronutrient amount measured in ppm, was higher in fortified rice (Fe, 43.54 ± 6.88; Zn, 36.7 ± 3.12) than in non-fortified rice (Fe, 4.24 ± 0.87; Zn, 9.3 ± 2.11). Hence, adopting appropriate cooking method, higher amount of micronutrients will be retained in the cooked food which will in turn help in combating the malnutrition and improve health.

Evaluation of Zinc Concentrations in Fruit from Various Pear Strains and Cultivars in China for Establishing a Standard for Zinc-Enriched Pears

“…Various sample pre-treatment methods are used when determining fruit Zn concentrations, including peeling, coring, sectioning, cleaning, drying, and digestion [19,20]. In our study, the digestion solution easily overflowed during the digestion of fresh and freezedried pear samples, and a long pre-digestion period at low temperatures was required.…”

Dietary zinc supplements: beneficial health effects and application in food, medicine and animals

“…136 With proper cooking methods, cooked foods will retain more micronutrients, thus helping to combat malnutrition and improve health. 137 Another popular carrier is dairy products. Compared to standard non-fortified milk, consumption of zinc-fortified drinking skim milk (Zn-Fmilk) increases very old cell-mediated immunity represented by thymosin activity and release of some cytokines (interleukin-12p70 and interferon-γ).…”

“…Furthermore, fortified rice has a high stability of micronutrients during storage, even at high temperatures and humidity, over a longer period of time 136 . With proper cooking methods, cooked foods will retain more micronutrients, thus helping to combat malnutrition and improve health 137 …”

Large-scale Fortification of Rice in India and Its Distribution in Public Distribution System

“…As of year 2022, seven countries have mandatory legislation for rice fortification, that is, Solomon Islands, Costa Rica, Nicaragua, Panama, Papua New Guinea, the Philippines, and the USA. Along with these, more than 86 countries are working and scaling fortification in cereals grain. High retention during cooking: Mohibbe et al (2021) reported that fortified polished rice had higher micronutrient contents (106.31 ± 12.56 mg iron and 97.72 ± 9.75 mg zinc) than non-fortified polished rice (7.44 ± 1.05 iron, 14.74 ± 2.94 mg zinc). During cooking, fortified rice suffered more percentage loss of micronutrients, as compared with non-fortified rice.…”

“…6. High retention during cooking: Mohibbe et al (2021) reported that fortified polished rice had higher micronutrient contents (106.31 ± 12.56 mg iron and 97.72 ± 9.75 mg zinc) than non-fortified polished rice (7.44 ± 1.05 iron, 14.74 ± 2.94 mg zinc). During cooking, fortified rice suffered more percentage loss of micronutrients, as compared with non-fortified rice.…”