Bioaktivitas Hidrolisat Protein Produk Samping Ikan Tenggiri Hasil Fermentasi Menggunakan Pediococcus pentosaceus IL13

Abstract

Produksi dan pengolahan ikan menghasilkan produk samping yang belum dimanfaatkan secara optimal. Produk samping ikan tenggiri (Scomberomorus commerson), khususnya daging sisa dan kulit, kaya protein dan kolagen sehingga berpotensi sebagai sumber peptida bioaktif. Penelitian ini bertujuan mengkaji bioaktivitas hidrolisat protein produk samping ikan tenggiri hasil fermentasi Pediococcus pentosaceus IL13 melalui pendekatan in vitro, in silico, peptidomics, dan metabolomics. Produk samping daging, kulit, dan campuran daging-kulit (1:1) difermentasi menggunakan P. pentosaceus IL13, kemudian hidrolisat kasar difraksinasi secara ultrafiltrasi menjadi fraksi <30, <10, dan <3 kDa. Identifikasi peptida dilakukan menggunakan LC-HRMS/MS setelah preparasi dengan digesti tripsin, sedangkan prediksi bioaktivitas, toksisitas, alergenisitas, serta aktivitas antidiabetes dan antimikroba dilakukan secara in silico. Untargeted metabolomics berbasis LC-HRMS digunakan untuk mengidentifikasi metabolit yang berpotensi berkontribusi terhadap bioaktivitas. Hasil menunjukkan bahwa fermentasi meningkatkan derajat hidrolisis dan menghasilkan hidrolisat dengan bioaktivitas multifungsi. Fraksi <3 kDa secara konsisten menunjukkan aktivitas tertinggi. Hidrolisat kulit memiliki aktivitas antioksidan dan antiinflamasi terbaik, sedangkan hidrolisat campuran menunjukkan aktivitas antidiabetes tertinggi dengan IC50 a-glukosidase sebesar 34,692 mg/mL. Seluruh hidrolisat menghambat bakteri Gram-positif dan Gram-negatif, dengan aktivitas terkuat terhadap Listeria monocytogenes. LC-HRMS/MS mengidentifikasi 211 sekuens peptida, terutama terkait kolagen, miosin, dan aktin. Peptida representatif diprioritaskan; sebagian besar diprediksi novel, tidak toksik, dan tidak alergenik. Peptida TGPIGMPGAR dan RLNFDAFLPMLK menunjukkan afinitas tinggi terhadap Keap1 dan TNF-a. Metabolomics mengidentifikasi taurin, asam amino, kreatin, kreatinin, dan metabolit lain yang berpotensi berkontribusi terhadap aktivitas biologis. Temuan ini menunjukkan bahwa fermentasi dan ultrafiltrasi efektif meningkatkan nilai tambah produk samping ikan tenggiri sebagai sumber bahan pangan fungsional dan nutraseutikal berkelanjutan.

Fish production and processing generate products that remain underutilized. Mackerel by-products (Scomberomorus commerson), including residual muscle and skin, are rich in protein and collagen and represent sources of bioactive peptides. This study aimed to evaluate the bioactivities of protein hydrolysates from mackerel by-products fermented with Pediococcus pentosaceus IL13 using in vitro, in silico, peptidomic, and metabolomic approaches. Muscle, skin, and muscle-skin (1:1) by-products were fermented with P. pentosaceus IL13, and crude hydrolysates were fractionated by ultrafiltration into <30, <10, and <3 kDa fractions. Peptides were identified by LC-HRMS/MS following tryptic digestion, while bioactivity, toxicity, allergenicity, antidiabetic, and antimicrobial potentials were predicted in silico. Untargeted LC-HRMS metabolomics was performed to identify metabolites potentially contributing to bioactivity. Fermentation increased the degree of hydrolysis and produced hydrolysates with multifunctional bioactivities. The <3 kDa fraction consistently exhibited the highest activities. Skin hydrolysate showed the strongest antioxidant and anti-inflammatory activities, whereas the mixed hydrolysate exhibited the highest antidiabetic activity, with an a-glucosidase inhibition IC50 of 34.692 mg/mL. All hydrolysates inhibited Gram-positive and Gram-negative bacteria, with the strongest activity against Listeria monocytogenes. LC-HRMS/MS identified 211 peptide sequences, mainly associated with collagen, myosin, and actin. Selected peptides were prioritized, with most predicted to be novel, non-toxic, and non-allergenic. TGPIGMPGAR and RLNFDAFLPMLK showed high binding affinities toward Keap1 and TNF-a, respectively. Metabolomics identified taurine, amino acids, creatine, creatinine, and metabolites potentially contributing to bioactivities. These findings demonstrate that fermentation combined with ultrafiltration can enhance the value of mackerel by-products as sustainable sources of functional food and nutraceutical ingredients.