Pengembangan Nasi Instan Freeze Dried dengan Pretreatment Osmotic Dehydration Larutan CaCl2: Kajian Kualitas Fisik, Rehidrasi, dan Tekstur

Iffah Uswatun Azizah, Dr. Eng. Annie Mufyda Rahmatika, S.T., M.T.

2026 | Tugas Akhir | D4 Pengembangan Produk Agroindustri

Metode freeze drying sering menyebabkan masalah pada integritas struktur dan tekstur nasi instan. Masalah ini timbul akibat perubahan struktur pati selama proses pengeringan beku. Struktur yang rapuh tersebut perlu diperkuat sebelum pengeringan. Kalsium klorida (CaCl₂) merupakan firming agent yang memperkuat matriks pati melalui pembentukan ikatan koordinasi ion Ca²? dengan gugus hidroksil pati. Oleh karena itu, penelitian ini menerapkan pretreatment osmotic dehydration menggunakan larutan CaCl? sebelum pembekuan dan pengeringan beku. Penelitian ini bertujuan menganalisis pengaruh konsentrasi CaCl₂ dan lama perendaman terhadap kualitas fisik, rehidrasi, dan tekstur nasi instan freeze dried. Penelitian ini menggunakan Rancangan Acak Lengkap (RAL) faktorial dengan dua faktor: konsentrasi CaCl₂ (0,5%; 1%; 1,5%) dan lama perendaman (30, 60, 90 menit). Tahapan penelitian meliputi penimbangan, pencucian I, pemasakan, pencucian II, penirisan, dan pengeringan beku. Parameter yang dianalisis meliputi kerusakan butiran, densitas, SEM, waktu rehidrasi, daya rehidrasi, rasio volume pengembangan, dan tekstur (hardness, cohesiveness, adhesiveness, dan chewiness). Data dianalisis secara statistik menggunakan Two-Way ANOVA pada taraf signifikansi 5%. Hasil penelitian menunjukkan perlakuan CaCl₂ 1,5?ngan lama perendaman 90 menit merupakan perlakuan optimum. Perlakuan tersebut menurunkan kerusakan butiran hingga 37,33?n menghasilkan waktu rehidrasi 15,56 menit. Perlakuan ini juga meningkatkan nilai cohesiveness dan chewiness sehingga mendekati karakteristik nasi hangat. Dengan demikian, pretreatment osmotic dehydration dengan CaCl₂ memberikan keseimbangan terbaik antara kualitas fisik, rehidrasi, dan tekstur nasi instan freeze dried. 

The freeze-drying method often causes problems in the structural and textural integrity of instant rice. These problems arise from changes in starch structure during the freeze-drying process. This fragile structure needs to be strengthened before drying. Calcium chloride (CaCl₂) is a firming agent that reinforces the starch matrix through coordination bonds between Ca²⁺ ions and the hydroxyl groups of starch. Therefore, this study applied an osmotic dehydration pretreatment using a CaCl2 solution before freezing and freeze-drying. This study aims to analyze the effect of CaCl₂ concentration and soaking time on the physical quality, rehydration, and texture of freeze-dried instant rice. This study used a factorial Completely Randomized Design (CRD) with two factors: CaCl₂ concentration (0.5%; 1%; 1.5%) and soaking time (30, 60, 90 minutes). The research stages include weighing, washing I, cooking, washing II, draining, and freeze-drying. The parameters analyzed include grain damage, density, SEM, rehydration time, rehydration power, swelling volume ratio, and texture (hardness, cohesiveness, adhesiveness, and chewiness). Data were analyzed statistically using Two-Way ANOVA at a significance level of 5%. The results showed that the treatment with 1.5?Cl₂ and a 90-minute soaking time was the optimum treatment. This treatment reduced grain damage by up to 37,33% and rehydration time of 15,56 minutes. It also increased cohesiveness and chewiness values, bringing them closer to the characteristics of warm rice. Thus, the osmotic dehydration pretreatment with CaCl₂ provided the best balance between physical quality, rehydration, and texture of freeze-dried instant rice.

Kata Kunci : CaCl?, freeze dry, nasi instan, osmotic dehydration, rehidrasi