Pemanfaatan Whey Protein Keju dan Kitosan Cangkang Udang sebagai Coating Pengawet Salak Pondoh (Salacca edulis Reinw.)

Abstract

Salak pondoh mengalami penurunan produksi dan kebutuhan ekspor belum tercapai sebab pembusukan akibat kontaminasi mikroorganisme, serta termasuk buah tropis yang sulit disimpan pada suhu rendah dibandingkan buah subtropis, sehingga diperlukan coating buah untuk perlindungan dan pengurangan kerusakan. Whey protein terdenaturasi memilliki sifat biopolimer pencegah oksigen penyebab kebusukan, sedangkan kitosan sebagai antimikroba perlambat pembusukan. Metode menggunakan kuantitatif deskriptif dengan pembuatan kitosan cangkang udang melalui tahap demineralisasi, deproteinasi, deasetilasi, uji kadar air, kadar abu, rendemen, dan derajat deasetilasi dari uji FTIR, selanjutnya dikombinasikan larutan Whey-Kitosan melalui uji parameter susut bobot, indeks pembusukan, dan umur simpan. Selama 14 hari, formula 3 dengan konsentrasi tertinggi, yaitu 9% WPI, 0,9% kitosan, dan 3,6 mL gliserin menunjukkan efektivitas terbaik, dengan susut bobot terendah 28,36%, indeks pembusukan terendah 25,00%, dan umur simpan terlama 14 hari, dibandingkan dengan kontrol tanpa coating yang mencapai susut bobot 51,91%, indeks pembusukan 69,44%, dan umur simpan hanya 7 hari.

Salak pondoh has experienced declining production and export targets remain unmet due to spoilage from microbial contamination. As a tropical fruit, it is also harder to store at low temperatures than subtropical fruits, making fruit coating necessary to protect and reduce damage. Denatured whey protein exhibits biopolymer properties that prevent oxygen, a key cause of spoilage, from penetrating the fruit surface, while chitosan acts as an antimicrobial agent that slows spoilage. This study used a quantitative descriptive method, beginning with shrimp shell chitosan production through demineralization, deproteinization, and deacetylation, followed by characterization tests for moisture content, ash content, water-soluble chitosan yield, and degree of deacetylation via FTIR. The chitosan was then combined with WPI to form a coating applied to the fruit and evaluated for weight loss, decay index, and shelf life. Over 14 days, Formula 3 (9% WPI, 0.9% chitosan, 3.6 mL glycerin) performed best, with the lowest weight loss (28.36%), lowest decay index (25.00%), and longest shelf life (14 days), versus the uncoated control (51.91% weight loss, 69.44% decay index, 7-day shelf life).