Chemical and Sensory Properties of Waffles Supplemented with Almond Skins

Almonds are one of the most produced nuts worldwide and numerous studies have shown that they have nutritional and medicinal characteristics, which gives them the possibility of being applied in various products. However, several by-products are generated during their production, which have characteristics of interest but remain underutilised, namely, the almond skins. This work aimed to study samples of waffles supplemented with almond skins. The waffles were evaluated for their total polyphenol content, antioxidant capacity, total flavonoids, ortho-diphenols, soluble sugars, starch, texture, and colour. They were also sensorially evaluated using a panel of tasters specialised in this type of evaluation and a quantitative descriptive analysis test (QDA) sensory test. The results showed that the waffles with the highest levels of phenolic compounds as well as the highest antioxidant activity (by the ABTS, DPPH, and FRAP methods) were the waffles supplemented with 10% almond skin. The total phenol contents obtained for the prepared extracts varied between 0.127 mg GAE/g and 0.415 mg GAE/g, the flavonoid contents ranged from 0.067 mg CAE/g to 0.339 mg CAE/g and the ortho-diphenol contents varied between 0.163 mg ACE /g and 0.303 mg ACE/g. Regarding the quantification of soluble sugars, the values were presented in percentage of fresh weight, and ranged from 30.148 to 38.054%; regarding the quantification of starch, the percentages varied from 14.488 to 21.982%. Sensorially, we verified that the samples were statistically different in terms of the descriptors colour, roasted aroma, and dissolubility, with a higher score in these descriptors for the waffles with 10% of almond skin. This process of obtaining waffles, which can be industrialised, is interesting from both a nutritional point of view and for the possibility of creating new, differentiated, and innovative products.

Automated summary

Almonds are a highly produced nut worldwide and research has shown their nutritional and medicinal characteristics, which make them suitable for various products. This study focused on waffles supplemented with almond skins and evaluated them for polyphenol content, antioxidant capacity, flavonoids, starch, texture, color, and sensory attributes. The results indicated that waffles with 10% almond skin had the highest phenolic compounds and antioxidant activity. The study also found variations in sugar and starch content among the waffles. Sensorial evaluation showed that the waffles with 10% almond skin had higher scores for color, roasted aroma, and dissolubility. This research highlights the potential of using almond skins in the production of innovative and nutritionally valuable products.