Analyzing the phenolic enriched fractions from Nixtamalization wastewater (Nejayote) fractionated in a three-step membrane process

Abstract

Nejayote is recognized as the main by-product resulting from the nixtamalization process of maize kernels, which is categorized as an alkaline residue with a chemical composition based on carbohydrates (37.8–55.7%), fiber (22.8–25.5%), protein (4.9–7.4%), and lipids (0.4–1.5%). In addition, Nejayote has an extensive content of simple (e.g., phenolic acids) and complex phenolic compounds (e.g., anthocyanins), which are responsible for the pigmentation and antioxidant activity of maize; therefore, there is a need of their identification depending on the type of maize. The current research has focused on the efficient extraction and identification of the phenolic acids contained in Nejayote after the processing of different types of maize. The target of this work was to fractionate Nejayote from white (NWM), red (NRM), and purple maize (NPM), using three different membranes, such as microfiltration (MF with a pore size of 1 μm) and ultrafiltration (UF100 and UF1 with a molecular weight cut-off of 100 kDa and 1 kDa, respectively), which were strategically applied to extract phenolic acids while retaining other molecules. Such a membrane system exhibited a retention in the first stage of almost all carbohydrates (MF-Retentate: ca. 12–19 g GE/L), while second stage (UF100-Permeate) a concentration of phenolic components was recovered ranging from 768 to 800 mg GAE/L. Finally, in the third stage (UF1-Permeate), 14 phenolic acids were identified, including ferulic and p- coumaric acids, derived from caffeic and ferulic acids, along with other molecules (e.g., glucose and fructose).

Nanofiltration-Assisted Concentration Processes of Phenolic Fractions and Carotenoids from Natural Food Matrices

“…The judicious concentration of carotenoids through nanofiltration enables meticulous control over color attributes, facilitating the fabrication of visually captivating foods without the reliance on synthetic colorants. Furthermore, the antioxidant potential inherent in specific carotenoids contributes substantively to the overall oxidative stability of lipid-laden food formulations [14].…”

“…Phenolic fractions, exhibiting anti-inflammatory, antimicrobial, and potentially anticancer attributes, have emerged as pivotal constituents in the synthesis of functional foods or pharmaceutical formulations. Meanwhile, carotenoids, acknowledged for their cutaneous health benefits and free-radicalquenching capabilities, are habitually incorporated into cosmetic formulations for skincare products [14].…”

Valorisation of food processing wastes using PEF and its economic advances – recent update

“…Phenolic compounds‐rich potato peels can be used in developing bioactive films with improved antioxidant activity, and mechanical strength (Zhao & Saldaña, 2019). Antioxidant‐rich phenolic compounds (p‐coumaric acids, ferulic acids and their derivatives) extracted from maize by‐products can be used as an enricher in functional foods with an additional nanofiltration process (Díaz‐Montes & Castro‐Muñoz, 2022).…”

“…In addition, the study also showed the various influencing factors of PEF (electric field intensity, solvent type and pulse number), HVED (time, solvent and frequency) and UAE (temperature, solvent and time) on anthocyanin extraction. As of now, the extracted anthocyanin is used as natural pigment in food, and colour indicator in intelligent packaging and gelatin films (Rawdkuen et al ., 2020; Fei et al ., 2021; Díaz‐Montes & Castro‐Muñoz, 2022) Therefore, PEF‐extracted anthocyanin can also be used in the same way.…”

Nejayote and Food Waste Leachate as a Medium for Scenedesmus acutus and Haematococcus pluvialis Production: A Mixture Experimental Design

“…In Latin America, where nixtamalized products are regarded as an absolute necessity, this by-product is produced in significant quantities due to the high demand for it. The conventional nixtamalization method requires as much as 7.5 L of water per kilogram of maize, which leads to the formation of nejayote [8]. This wastewater causes an environmental problem due to its alkalinity and biological demand for oxygen (DBO).…”