Effect of Beetroot Powder Incorporation on Functional Properties and Shelf Life of Biscuits

Abstract

The demand for ready-to-use functional foods is high, which encourages manufacturers to develop new, nutritionally valuable products. As an excellent source of biologically active compounds, beetroot (Beta vulgaris L.) is considered to have highly beneficial effects on health. This research aimed to evaluate the impact of replacing spelt flour (SF) with 15%, 20% and 25% beetroot powder (BP). The physicochemical and functional properties of biscuits baked at different temperatures (150 and 170 °C) were followed at the beginning, and after 3 and 6 months of storage as standard conditions. Moisture content and water activity (aw) gave insight into the biscuits’ shelf life. The value of aw from 0.35 to 0.56 indicated appropriate storability. Dietary fiber content in fresh biscuits ranged from 6.1% to 7.6%, protein from 9.2% to 8.9% and sugar from 30.6% to 35.9%. The content of betalain, total polyphenols and flavonoids, and antioxidant activity (DPPH, FRAP) increased with beetroot powder content incorporated. A slight decrease of all the mentioned parameters during the storage indicated satisfied retention of bioactive molecules. The content of prevalent phenolic compounds gallic and protocatechuic acid, identified by HPLC, decreased from 22.2–32.0 and 21.1–24.9 in fresh biscuits to 18.3–23.4 and 17.3–20.3 mg/100 g upon six months of storage, respectively. An increase of the L* and a* and a decrease of the b* coordinate values, compared with the control sample without beetroot values, was noticed as well as the expected level of their change during the storage. The obtained results indicated that biscuits enriched with beetroot powder showed a significantly improved functional, nutritional and antioxidant potential during storage.

Investigating the effect of red beetroot powder concentration and processing time on the bioactive compounds composition and antioxidant capacity of beetroot dark chocolate

“…Although earlier studies by Vulić et al 36 . and Mitrevski et al 13 . reported the presence of catechin and epicatechin in beetroot pomace extracts and powder, respectively, the present study did not detect catechin and epicatechin in the beetroot powder analyzed.…”

“…Dundar et al 38 . and Mitrevski et al 13 . also reported an increase in the TPC in biscuits and cookies enriched with beetroot powder and bee pollen, respectively.…”

“…In general, the total betalains content in the beetroot powder was 3.81 ± 0.02 mg g −1 (Table 3). Mitrevski et al 13 . and Kaur et al 35 .…”

“…Differences in the methods of preparing the beetroot powder and analyzing the betalains content could account for these variations. Mitrevski et al 13 . and Kaur et al 35 .…”

“…Ozaki et al 25 . utilized beetroot powders as nitrite substitutes in fermented dry sausages, and Mitrevski et al 13 . incorporated beetroot powder into biscuits.…”