Use of Almond Skins to Improve Nutritional and Functional Properties of Biscuits: An Example of Upcycling

• Published in: Foods Vol. 9; no. 11; p. 1705
• Main Authors: Pasqualone, Antonella, Laddomada, Barbara, Boukid, Fatma, Angelis, Davide De, Summo, Carmine
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 20-11-2020; MDPI
• Subjects: Almond; almond skins; Antioxidants; Biscuits; by-product; Byproducts; Circular economy; Color; Confectionery; Dietary fiber; Environmental impact; fiber; Flour; Food industry; Food processing industry; Food science; Friability; health claims; High-performance liquid chromatography; Impact analysis; Lipids; Liquid chromatography; Nutrient content; Nutritional aspects; Odor; Phenolic compounds; Phenols; Sensory evaluation; upcycling; Wheat; Germany; United States > US; Italy; by-product; biscuits; fiber; almond skins; phenolic compounds; upcycling; health claims; sensory properties; nutritional composition
• ISSN: 2304-8158; 2304-8158
• DOI: 10.3390/foods9111705

Upcycling food industry by-products has become a topic of interest within the framework of the circular economy, to minimize environmental impact and the waste of resources. This research aimed at verifying the effectiveness of using almond skins, a by-product of the confectionery industry, in the preparation of functional biscuits with improved nutritional properties. Almond skins were added at 10 g/100 g (AS10) and 20 g/100 g (AS20) to a wheat flour basis. The protein content was not influenced, whereas lipids and dietary fiber significantly increased (
< 0.05), the latter meeting the requirements for applying "source of fiber" and "high in fiber" claims to AS10 and AS20 biscuits, respectively. The addition of almond skins altered biscuit color, lowering
and
and increasing
, but improved friability. The biscuits showed sensory differences in color, odor and textural descriptors. The total sum of single phenolic compounds, determined by HPLC, was higher (
< 0.05) in AS10 (97.84 µg/g) and AS20 (132.18 µg/g) than in control (73.97 µg/g). The antioxidant activity showed the same trend as the phenolic. The
-hydroxy benzoic and protocatechuic acids showed the largest increase. The suggested strategy is a practical example of upcycling when preparing a health-oriented food product.