The Effect of Including Sea Buckthorn Berry By-Products on White Chocolate Quality and Bioactive Characteristics under a Circular Economy Context

The by-products of the extraction of sea buckthorn (<i>Hippophae rhamnoides</i> L.) concentrated juice may represent a functional food ingredient for white chocolate production, as a rich source of bioactive compounds. The effects of six treatments derived from the factorial combination of two types of by-products (with oil or without oil) and three different concentrations (5%, 10%, and 15%), were assessed on rheological, quality, colour, antioxidant, and mineral properties of chocolate. The 15% addition of full powder led to the highest values of max firmness, total shear energy, shear energy, cohesiveness, gummosity, dry matter, and ABTS, compared to the untreated control, but the two highest concentrations of the oil-deprived powder resulted in the protein content increasing. The full powder addition always raised fat levels. Both the 'L' and 'a' colour component as well as total carotenoids, β-carotene, lycopene, and vitamin C increased with the rise of <i>H. rhamnoides</i> powder addition, compared to the untreated control. The opposite trend was shown by the 'b' colour component and pH, whereas polyphenols and antioxidant activity attained higher values with the oil-deprived powder. The content of potassium decreased upon the 15% addition of the <i>Hippophae rhamnoides</i> by-product powder, compared to the untreated control, whereas calcium and magnesium increased. The 15% <i>H. rhamnoides</i> full powder elicited the augmentation of phosphorus content in chocolate, compared to the untreated control, contrary to the effect of the oil-deprived powder on P and Zn. The employment of SBB by-products highlights the great potential for manufacturing innovative functional foods with high nutritional value, such as chocolate.