The Bioaccessibility of Phenolics, Flavonoids, Carotenoids, and Capsaicinoid Compounds: A Comparative Study of Cooked Potato Cultivars Mixed with Roasted Pepper Varieties

Abstract

An in vitro method was used to assess the bioaccessibility of phenolics, flavonoids, carotenoids, and capsaicinoid compounds in different cooked potatoes mixed with roasted peppers (Capsicum annuum), Joe Parker (JP, hot), and Sweet Delilah (SD, sweet). The present study identified differences in the bioaccessibility of bioactive compounds among the potato cultivars (Solanum tuberosum) Purple Majesty (PM; purple flesh), Yukon Gold (YG; yellow flesh), Rio Grande Russet (RG; white flesh) and a numbered selection (CO 97226-2R/R (R/R; red flesh)). The bioactive compounds and capsaicinoid compounds in potatoes and peppers were estimated before and after in vitro digestion. Before digestion, the total phenolic content of potato cultivars mixed with JP was in the following order: R/R > PM > YG > RG. The highest levels of carotenoids were 194.34 µg/g in YG and 42.92 µg/g in the RG cultivar when mixed with roasted JP. The results indicate that the amount of bioaccessible phenolics ranged from 485 to 252 µg/g in potato cultivars mixed with roasted JP. The bioaccessibility of flavonoids ranged from 185.1 to 59.25 µg/g. The results indicate that the YG cultivar mixed with JP and SD showed the highest phenolic and carotenoid bioaccessibility. In contrast, the PM mixed with JP and SD contained the lowest phenolic and carotenoid bioaccessibility. Our results indicate that the highest flavonoid bioaccessibility occurred in R/R mixed with roasted JP and SD. The lowest flavonoids bioaccessibility occurred in PM and the RG. The maximum bioaccessible amount of capsaicin was observed in YG mixed with JP, while the minimum bioaccessibility was observed with PM.

Compositional Changes in Potato Carbohydrates and Polyphenols during In vitro Gastrointestinal Digestion

“…The quantification of individual phenolics was carried out as described by Albishi et al. [1 7 ] A reverse phase column (250 × 4.6 mm, 5 µm Purospher RP‐18e, Merck, Germany) was used on the LaChrom HPLC system (Merck‐Hitachi Darmstadt, Germany). The injection volume was 20 µL (injected in rheodyne injector) and the wavelength used was 324 nm.…”

“…Cooking of potatoes mixed with peppers is reported to enhance the bioaccessibility of polyphenolics. [7] The cooking methods also result in physical, chemical, and enzymatic modification of phytochemicals leading to sensory, and textural changes in food. [8,9] However, cooking may also cause the loss of some of phytonutrients and the formation of undesired products.…”

In vitro bioaccessibility of biguanide‐related compounds and phenolics from yellow, red, and purple‐fleshed potatoes

“…6 One major factor that affects bioaccessibility is food processing which can increase some phytonutrients and decrease others. 6 Till date, bioaccessibility of acrylamide, 7 phenolics, flavonoids, carotenoids, 8 vitamin C, 9 lutein, and zeaxanthin 10 has been studied in potatoes.…”

“…Hamed et al (2021) reported mixing roasted peppers, namely, cultivars Joe Parker and Sweet Delilah with the potato cultivar Yukon Gold (yellow flesh) to significantly enhance the bioaccessibility of polyphenols and carotenoids. 8 As reviewed by Thakur et al, the change in pH in gut environment affects the bioaccessibility of phytonutrinets. Researchers have reported decrease in concentration of bioaccessible phytonutrients such as total polyphenols, flavonoids, and anthocyanins when shifted from acidic gastric phase to alkaline intestinal phase.…”

“…In simple terms, bioaccessibility is defined as the “ingested compound released from its food matrix and becomes available for absorption in the intestine.” 6 One major factor that affects bioaccessibility is food processing which can increase some phytonutrients and decrease others 6 . Till date, bioaccessibility of acrylamide, 7 phenolics, flavonoids, carotenoids, 8 vitamin C, 9 lutein, and zeaxanthin 10 has been studied in potatoes. The ingredients used during the processing of vegetables are also known to influence the bioaccessibility of phytochemicals.…”