Biowaste as a Potential Source of Bioactive Compounds—A Case Study of Raspberry Fruit Pomace

Abstract

Raspberry fruit pomace, a byproduct of juice production, was studied as a potential source of antioxidant compounds. Target high-performance liquid chromatography analysis of important polyphenolic compounds (gallic, p-coumaric, caffeic, quercitrin, chlorogenic, and ellagic acid) was performed together with analysis of total phenolic content (TPC), total flavonoid content (TFC), total anthocyanins content (TAC), and antioxidant capacity (via ferric reducing antioxidant power (FRAP) and 1,1-diphenyl-2-picrylhydrazyl (DPPH) assays). The differences in polyphenolic content of Rubus idaeus L. pomace were evaluated following ultrasound-assisted extraction and conventional maceration with different organic solvents. Additionally, the yield of free phenolics was measured in hydrolyzed pomace extracts. The results obtained show that the ultrasound method maximizes the quantity of antioxidant compounds in terms of TPC (27.79 mg/L gallic acid equivalent (GAE)), TFC (8.02 mg/g quercetin equivalent (QE)), TAC (7.13 mg/L cyanidine-3-glucoside equivalent (C3G Eq)), caffeic (19.17 µg/g), chlorogenic (3.56 µg/g), ellagic (105.52 µg/g), and gallic acids (8.75 µg/g), as well as FRAP (1002.72 µmol/L) and DPPH assays (969.71 µmol/mL vitamin C equivalent (vit C Eq); 567.00 µmol/100 g Trolox equivalent (TE)). On the other hand, conventional maceration maximizes the yield of quercetin and p-coumaric acid. In terms of biowaste valorization, raspberry fruit pomace has a promising industrial potential and may prove to be useful in the development of antioxidant dietary supplements.

Alternative Methods of Bioactive Compounds and Oils Extraction from Berry Fruit By-Products—A Review

“…Krivokapić et al [107] examined raspberry pomace extraction using the UAE method and compared it to conventional maceration. UAE was conducted in an ultrasonic cleaner for 20 min at 50 • C and 50 kHz with acidulated methanol as a solvent.…”

Spectrum–effect relationship between ultra‐high‐performance liquid chromatography fingerprints and antioxidant activities of Lophatherum gracile Brongn

“…The ability to reduce ferric ions was measured based on previous articles (Krivokapic et al., 2021 ; Tadic et al., 2021 ) with minor revisions. The stock solutions included 300 mM acetate buffer, pH 3.6, 10 mM 2,4,6‐Tris(2‐pyridyl)‐s‐triazine (TPTZ) solution in 40 mM HCl and 20 mM FeCl 3 .6H 2 O solution.…”

Mineral Content and Volatile Profiling of Prunus avium L. (Sweet Cherry) By-Products from Fundão Region (Portugal)

“…According to the literature, more than 20% of fruits and vegetables are transformed into waste [ 17 ], and the scientific community has developed an interest in these bio-residues, as they represent a source of functional substances whose recovery can generate economic value, contributing to waste reduction [ 2 , 18 ] and the circular economy. Prunus avium L., sweet cherry, is a member of the Rosaceae family and is a well-known and very popular fruit worldwide due to its organoleptic properties and nutritional or health benefits [ 3 , 19 ].…”