Fiber concentrates from raspberry and blueberry pomace in gluten‐free cookie formulation: Effect on dough rheology and cookie baking properties

Abstract

Raspberry and blueberry pomace, by‐products from fruit juice industry, were dehydrated to obtain fruit fiber concentrates and valorized as ingredients in gluten‐free (GF) cookies formulation. The aim was to evaluate the effect of substituting 30% (w/w) of GF flour mixture with different ratios of blueberry/raspberry fiber concentrates (0/30, 15/15, and 30/0) on rheological properties of cookie dough and cookie baking quality. Generally, the incorporation of the fiber concentrates increased the elastic and the viscous moduli thus producing harder doughs and consequently firmer cookies in comparison to the control. Although having similar total, soluble and insoluble fiber content, blueberry fiber concentrates were characterized with higher water absorption capacity and consequently yielded cookies with more rigid dough structure, higher water loss during baking, lower cookie thickness, higher spread ratio, more dense inner structure, and increased cookie hardness than those containing raspberry fiber concentrates. Enrichment of GF cookies with raspberry and blueberry fiber concentrates resulted in products with dietary fiber content higher than 6 g per 100 g, thus making them candidates for bearing “high fiber” nutrition claim. Practical applications Currently available GF bakery products mostly lack dietary fibers (DFs) and other important nutrients, because they are usually manufactured from refined flour and/or starches. As the products with long shelf‐life, very popular in daily diet of almost all consumer profiles, cookies could represent good matrices for the addition of functional ingredients, such as DFs. In this paper, GF cookies were enriched with the fiber concentrates recovered from blueberry and raspberry pomace. Application of these fiber sources enabled recycling of fruit processing industry by‐products into novel, “high fiber” GF product with improved nutritive profile.

Gluten‐free cookies added with fibre and bioactive compounds from blackcurrant residue

“…The water activity was 0.733 ± 0.004 and 0.740 ± 0.001 for C‐cookies and B‐cookies, respectively, with no significant differences. The higher water content but same water activity of B‐cookie may be due to the fibre contribution to the water binding capacity and the presence of low molecular weight compounds given by the fruit ingredient, which could provide water interaction sites and could also decrease the water activity (Šarić et al ., 2019; Reißner et al ., 2019).…”

“…Regarding the fibre content, Šarić et al . (2019) enriched gluten‐free cookies with raspberry concentrates (by replacing 30% of the gluten‐free flour) and reached a TDF content of 6.92 ± 0.018% d.b. In this work, a lower addition of blackcurrant ingredient significantly enhanced the TDF content by 2.5 times as well as the IDF by 2.7 times.…”

“…There is nowadays a great variety of gluten‐free products in the market. However, the refined flours and starches used as a replacement of wheat (typically rice flour and corn or potato starch) have small quantities of fibre and thus result in food with a very poor nutritional profile in terms of this nutrient (Šarić et al ., 2019). The beneficial effects of a diet rich in fibres include prevention of constipation, the control of serum cholesterol levels, the reduction of the risk of diabetes and intestinal cancer, and the stimulation of beneficial microorganisms (Perry & Ying, 2016).…”

Olive Cake Powder as Functional Ingredient to Improve the Quality of Gluten-Free Breadsticks

“…Moreover, the textural properties of final products may be affected by the nature of the fibres (soluble or insoluble), as well as size, morphology, and technological properties such as water binding and holding capacity, which can affect the water content of the end product [ 62 , 79 , 80 ]. According to Šarić et al [ 81 ], the positive correlation existing between a high amount of water in the system and the lower breaking force (hardness) of gluten-free cookies with added blueberry pomace derives from the penetration of water in the starch granules, which swelled. This phenomenon determined an increase in intramolecular bond breakage and macromolecule mobility, with a consequently less-dense cookie structure and lower breaking force.…”

Effect of Issatchenkia terricola WJL-G4 on Deacidification Characteristics and Antioxidant Activities of Red Raspberry Wine Processing

“…However, industrial development of red raspberry products got restricted due to the limitation in preservation and processing techniques [10]. In the international market, the processed products of red raspberry include food drinks [11], baked products [12], leisure ready-to-eat products [13], frozen foods [14], while the research on red raspberry products in China is limited.…”