Karakteristik Fisik, Kimia dan Sifat Foaming Foam-Mat Dried Murbei (Morus nigra L.) dengan Variasi Agen Pembusa dan Konsentrasi Guar Gum

Abstract

Black mulberry (Morus nigra L.) is rich in anthocyanins and phenolic compounds with high antioxidant activity, but its high moisture content and heat sensitivity result in a short shelf life. Foam-mat drying is suitable for producing mulberry powder because it enables low-temperature drying and better quality retention, although its success depends on foam quality influenced by foaming agents and stabilizers. This study evaluated the effects of foaming agents (Tween 80 and TBM) and guar gum concentrations (0.12, 0.16, and 0.20%) on the foaming, physical, and chemical properties of foam-mat dried black mulberry powder using a factorial Randomized Block Design with six treatments. Observed parameters included foaming capacity and stability, color (L*, a*, b*), TSS, moisture, ash, protein, total sugar, vitamin C, pH, anthocyanin content, antioxidant activity (FRAP), and TTA. Foaming capacity (546.87–593.21%) and stability (70.56–96.56%) increased significantly with higher guar gum concentration (P < 0.05). Color values L* (38.31–57.40), a* (7.63–12.80), and b* (4.70–6.98) were significantly affected, with Tween 80 producing brighter powder and better red color retention. TSS ranged from 8.74–9.94 °Brix and was higher in TBM treatments due to sugar and polyol content. Moisture content decreased with guar gum (3.28–4.59%), while ash (0.81–0.94%) and total sugar (75.61–93.75%) were not significantly affected. Protein content (0.77–1.28%) was influenced by both factors, with TBM giving higher values. Vitamin C (78.71–117.82 mg/100 g) increased with foam stability, especially in TBM. pH (3.21–3.59) showed an inverse relationship with TTA (12.35–15.59%). Anthocyanins (239.00–447.34 mg/100 mg) and antioxidant activity (13.02–17.36 µmol TE/g) increased with guar gum concentration and were higher in Tween 80 treatments. Based on MCDM analysis, the best treatment was Tween 80 with 0.20% guar gum, producing powder with optimal foaming properties, low moisture, and high retention of bioactive compounds. Keywords: black mulberry, foam-mat drying, foaming agent, guar gum, powdered beverage, anthocyanins.