Hazelnut Shells as Source of Active Ingredients: Extracts Preparation and Characterization

• Published in: Molecules (Basel, Switzerland) Switzerland), 2021-10, Vol.26 (21), p.6607
• Main Authors: Di Michele, Alessandro, Pagano, Cinzia, Allegrini, Agnese, Blasi, Francesca, Cossignani, Lina, Raimo, Enrico Di, Faieta, Marco, Oliva, Eleonora, Pittia, Paola, Primavilla, Sara, Sergi, Manuel, Vicino, Camilla, Ricci, Maurizio, Schirone, Bartolomeo, Perioli, Luana
• Format: Article
• Language: English
• Subjects: Anti-Bacterial Agents - chemistry; Anti-Bacterial Agents - isolation & purification; Anti-Bacterial Agents - pharmacology; Antiinfectives and antibacterials; Antioxidants; Antioxidants - chemistry; Antioxidants - isolation & purification; Antioxidants - pharmacology; Bacillus cereus - drug effects; Bacillus subtilis - drug effects; Benzothiazoles - antagonists & inhibitors; Biphenyl Compounds - antagonists & inhibitors; By products; Catechin; Chemical analysis; Chemical composition; Chlorogenic acid; Corylus - chemistry; extracts; Food; Gallic acid; hazelnut shells by-products; Hazelnuts; Investigations; Leaves; Maceration; Methods; Microbial Sensitivity Tests; Pharmaceuticals; Phenolic compounds; Phenols; Picrates - antagonists & inhibitors; Plant Extracts - chemistry; Plant Extracts - isolation & purification; Plant Extracts - pharmacology; Polyphenols; Protocatechuic acid; Shells; Solvents; Sulfonic Acids - antagonists & inhibitors; ultrasonic bath; Ultrasonic imaging; Ultrasonic methods; valorization; waste; Waste materials
• ISSN: 1420-3049; 1420-3049
• DOI: 10.3390/molecules26216607

Hazelnut shells represent a waste material (about 42% of the total biomass) deriving from hazelnut harvest. These are mainly used as a heating source; however, they represent an interesting source of polyphenols useful in health field. The impact on phenolic profile and concentrations of hazelnut shell extracts obtained by three extraction methods (maceration, ultrasonic bath, and high-power ultrasonic), as well as temperature, extraction time, and preventive maceration, was studied. The prepared extracts were characterized in terms of chemical composition, antioxidant and antimicrobial activities. Eighteen different phenolic compounds were identified and quantified by chemical analysis and gallic acid was the most abundant in all the extracts analyzed. Other relevant compounds were chlorogenic acid, protocatechuic acid and catechin. Preventive maceration had a positive effect on the extraction of different types of compounds regardless of the method performed. Application of the high-power ultrasonic method had different effects, either positive or negative, depending on the type of compound and extraction time. All the prepared extracts showed antioxidant activity especially those prepared by maceration, and many of them were able to inhibit the growth of both and .