Pengaruh Pengolahan Sayur Bayam Berkuah terhadap Kadar Oksalat dan Bioaksesibilitas Zat Besi

Abstract

Bayam (Amaranthus sp.) merupakan salah satu sumber zat besi non-heme yang dapat berkontribusi dalam pemenuhan kebutuhan zat besi sebagai upaya pencegahan anemia, tetapi kandungan oksalat dapat menghambat bioaksesibilitas zat besi melalui pembentukan kompleks yang sukar larut. Penelitian ini bertujuan menganalisis pengaruh pengolahan sayur bayam berkuah terhadap kadar oksalat larut air, kadar zat besi, vitamin C, dan bioaksesibilitas zat besi secara in vitro. Penelitian menggunakan Rancangan Acak Lengkap dengan tiga perlakuan, yaitu bayam rebus tanpa bumbu (P0), sayur bening bayam dengan tomat (P1), dan sayur bobor bayam dengan santan dan bumbu (P2). Sampel berupa sayur bayam beserta kuahnya dihomogenkan sebelum dianalisis. Analisis meliputi kadar oksalat menggunakan spektrofotometer kinetik, kadar zat besi dengan Atomic Absorption Spectrophotometry (AAS), vitamin C, proksimat, serta simulasi pencernaan in vitro metode INFOGEST 2.0. Hasil menunjukkan bahwa pengolahan bayam berkuah menurunkan kadar oksalat larut air secara signifikan (p<0,05), dari 1,49±0,03 mg/100 g%bk (P0) menjadi 0,58±0,01 mg/100 g%bk (P1) dan 0,47±0,01 mg/100 g%bk (P2). Perlakuan P1 memiliki kadar zat besi, vitamin C, dan bioaksesibilitas zat besi tertinggi. Dengan demikian, pengolahan bayam menjadi sayur bening dengan penambahan tomat meningkatkan bioaksesibilitas zat besi melalui penurunan kadar oksalat larut air dan peningkatan kandungan vitamin C.

Spinach (Amaranthus sp.) is a source of non-heme iron that can contribute to meeting iron requirements as part of anemia prevention. However, its oxalate content may reduce iron bioaccessibility by forming poorly soluble complexes. This study aimed to analyze the effects of processing spinach soup dishes on water soluble oxalate, iron, vitamin C, and in vitro iron bioaccessibility. A Completely Randomized Design with three treatments was employed: boiled spinach without seasonings (P0), clear spinach soup with tomato (P1), and spinach cooked in coconut milk with seasonings (P2). The spinach dishes, including both the leaves and broth, were homogenized before analysis. The analyses included water-soluble oxalate using kinetic spectrophotometry, iron using Atomic Absorption Spectrophotometry (AAS), vitamin C, proximate composition, and in vitro iron bioaccessibility using the INFOGEST 2.0 digestion model. The results showed that processing spinach into soup dishes significantly reduced water-soluble oxalate content (p<0.05), from 1.49±0.03 mg/100 g dry basis (P0) to 0.58±0.01 mg/100 g dry basis (P1) and 0.47±0.01 mg/100 g dry basis (P2). Treatment P1 had the highest iron content, vitamin C content, and iron bioaccessibility. Therefore, processing spinach into clear soup with tomato enhanced iron bioaccessibility by reducing water-soluble oxalate content and increasing vitamin C content.