Maize Processing Waste Water Upcycling in Mexico: Recovery of Arabinoxylans for Probiotic Encapsulation

Abstract

Maize is a major source of food in Mexico. In order to improve its nutritional value, maize kernel is exposed to an alkali treatment that generates large volumes of waste water containing gelling arabinoxylan. The purpose of the present study was to evaluate the capability of maize waste water arabinoxylans (MWAX) to encapsulate probiotics. The rheological, structural, and microstructural characteristics of this bio-based material were also investigated. MWAX gels at 10% (w/v) were able to encapsulate Bifidobacterium as probiotic model. The MWAX gel containing 1 × 10 7 CFU/mL of probiotics presented a storage (G ) and loss (G") moduli of 50 and 11 Pa, respectively. The average mesh size of the MWAX gel was around 11 times smaller than the Bifidobacterium cell magnitude. MWAX gels with or without probiotics were studied using scanning electron microscopy. The interior of the Bifidobacterium loaded gels was composed of a pore-like network of MWAX through which probiotics were distributed. The probiotic encapsulating MWAX gels appeared to be less porous than the empty gels. MWAX capability to encapsulate Bifidobacterium may be important in designing probiotic encapsulating biodegradable gels and could represent an opportunity in sustainable food waste management and utilization through upcycling to value-added products.

Partial removal of protein associated with arabinoxylans: Impact on the viscoelasticity, crosslinking content, and microstructure of the gels formed

“…The AX gel showed a heterogeneous microstructure, which can be compared to an irregular honeycomb. Similar microstructures have been reported previously for lyophilized maize and wheat AX gels . AXD and AXP gels [Figure (b,c)] showed a more homogeneous and compact microstructure in comparison to AX gel.…”

“…The mechanical spectra of AX, AXD, and AXP gels [Figure (b)] after 1 h of gelation exhibited a typical solid‐like material behavior with a linear G′ independent of frequency, and G″ much smaller than G′ and dependent on frequency . Similar behavior has been reported previously for maize AX gels . Stability of hydrogels is a relevant feature when considering its application in food or pharmaceutical industry as these materials must keep their properties throughout their shelf life.…”

“…for maize bran AX at the same concentration (2% w/v). Lower G′ values (2–421 Pa) have been reported for other laccase‐induced maize bran AX, at higher concentrations (4–10% w/v) . Such behavior might be related to the structural and/or conformational characteristics of these molecules, particularly the FA content.…”

“…AX gels have potential application as matrices for controlled release of biomolecules, cells for food or biomedical industries, among others . These gels have the ability to entrap and control the release of model biomolecules such as lycopene, lactoglobulin, and insulin .…”

“…These gels have the ability to entrap and control the release of model biomolecules such as lycopene, lactoglobulin, and insulin . In addition, they can be used for the encapsulation of yeast and probiotic bacteria (Bifidobacteria) . Recently, the entrapment of probiotic bacteria (Bifidobacteria) and insulin in core–shell AX gel particles were evaluated.…”