RESUMEN
BACKGROUND: Nixtamalized flour snacks such as tortilla chips are widely consumed across the world, but they are nutritionally poor and contribute to obesity and other non-communicable diseases. The production of healthy versions of such snacks, by incorporating vegetables and improving the quality of the flours used in their formulation, could help address these nutritional challenges. This study compared the fortification of baked tortilla chips with vegetable leaf powders (kale and wild amaranth at 0%, 4%, 8%, and 16% w/w) and using two types of nixtamalized flour: traditional (TNF) and with ohmic heating (OHF). RESULTS: Overall, the use of OHF increased 1.88 times the fibre in enriched and non-enriched snacks with respect to TNF, but the latter had 1.85 times more protein. Addition of 16% of vegetable powders increased protein (kale = 1.4-fold; amaranth = 1.3-fold) and dietary fibre (kale = 1.52-fold; amaranth = 1.7-fold). Amaranth enrichment improved total phenolic content (TPC) and total flavonoid content (TFC) of chips at least 1.2 and 1.63 times, respectively. OHF chips also had higher bound TPC than TNF ones, regardless of vegetable addition. Combinations of OHF with 16% amaranth produced chips 1.74-fold higher in antioxidant capacity than non-enriched ones, due to increased content of phenolics such as ferulic acid. CONCLUSION: This work showed that tortilla chips made using nixtamalized flour produced with assisted ohmic heating, alone or in combination with wild amaranth leaf powder, could be used in the production of healthy maize snacks to enhance their prospective antioxidant activity and nutritional value. © 2023 Society of Chemical Industry.
Asunto(s)
Amaranthus , Brassicaceae , Verduras/metabolismo , Harina/análisis , Manipulación de Alimentos/métodos , Bocadillos , Calefacción , Estudios Prospectivos , Suplementos Dietéticos , Antioxidantes/análisis , Fenoles/análisis , Brassicaceae/metabolismo , Amaranthus/químicaRESUMEN
The fruit of Guamúchil is an excellent source of bioactive compounds for human health although their natural occurrence could be affected by the ripening process. The aim was to evaluate some physicochemical, chemical and antioxidant changes in guamúchil fruit during six ripening stages (I to VI). A defined trend (p ≤ 0.003) was observed for color [°Hue, 109 (light green) to 20 (dark red)], anthocyanins (+571 %), soluble solids (+0.33 oBrix), ash (+16 %), sucrose (-91 %), proanthocyanidins (63 %), ascorbic acid (-52 %) and hydrolysable PC (-21 %). Carotenoids were not detected and chlorogenic acid was the most abundant phenolic compound. Maximal availability of these bioactives per ripening stage (p ≤ 0.03) was as follows: I (protein/ lipids/ sucrose/ proanthocyanidins/ hydrolysable phenolics), II (total sugars/ascorbic acid), III (total phenolics), IV (flavonoids/ chlorogenic acid) and VI (fructose/ glucose/ anthocyanins). Color change was explained by sucrose (ß = 0.47) and anthocyanin (ß = 0.20) contents (p < 0.001). Radical scavenging capacity (ORAC, DPPH and TEAC) strongly correlated with total PC (r = 0.49-0.65, p ≤ 0.001) but 89 % of ORAC's associated variance was explained by anthocyanin + sucrose + ascorbic acid (p ≤ 0.0001). Guamúchil fruit could be a more convenient source of specific bioactive compounds if harvested at different ripening stages.