The preparation of phytosteryl succinyl sucrose esters and improvement of their water solubility and emulsifying properties

Advances and Challenges in Plant Sterol Research: Fundamentals, Analysis, Applications and Production

Plant sterols (PS) are cholesterol-like terpenoids widely spread in the kingdom Plantae. Being the target of extensive research for more than a century, PS have topped with evidence of having beneficial effects in healthy subjects and applications in food, cosmetic and pharmaceutical industries. However, many gaps in several fields of PS's research still hinder their widespread practical applications. In fact, many of the mechanisms associated with PS supplementation and their health benefits are still not fully elucidated. Furthermore, compared to cholesterol data, many complex PS chemical structures still need to be fully characterized, especially in oxidized PS. On the other hand, PS molecules have also been the focus of structural modifications for applications in diverse areas, including not only the above-mentioned but also in e.g., drug delivery systems or alternative matrixes for functional foods and fats. All the identified drawbacks are also superimposed by the need of new PS sources and technologies for their isolation and purification, taking into account increased environmental and sustainability concerns. Accordingly, current and future trends in PS research warrant discussion.

Ionic liquid-mediated regeneration of cellulose dramatically improves decrystallization, TEMPO-mediated oxidation and alkyl/alkenyl succinylation

This work demonstrated a successful strategy that simple ionic liquids (ILs) mediated pretreatment could effectively reduce crystallinity of cellulose from 71 % to 46 % (by C₂MIM.Cl) and 53 % (by C₄MIM.Cl). The IL-mediated regeneration of cellulose greatly promoted its reactivity for TEMPO-catalyzed oxidation, which the resulting COO^- density (mmol/g) increased from 2.00 for non-IL-treated cellulose to 3.23 (by C₂MIM.Cl) and 3.42 (C₄MIM.Cl); and degree of oxidation enhanced from 35 % to 59 % and 62 %, respectively. More significantly, the yield of oxidized cellulose increased from 4 % to 45-46 %, by 11-fold. IL-regenerated cellulose can also be directly subjected to alkyl/alkenyl succinylation without TEMPO-mediated oxidation, producing nanoparticles with properties similar to oxidized celluloses (55-74 nm in size, -70-79 mV zeta-potential and 0.23-0.26 PDI); but in a much higher overall yield (87-95 %) than IL-regeneration-coupling-TEMPO-oxidation (34-45 %). Alkyl/alkenyl succinylated TEMPO-oxidized cellulose showed 2-2.5 times higher ABTS* scavenging ability than non-oxidized cellulose; however, alkyl/alkenyl succinylation also resulted in a significant decline in Fe²⁺ chelating property.

Synthesis, Physical Properties, and In Vitro-Simulated Gastrointestinal Digestion of Hydrophilic β-Sitosterol Sugar Esters

Hydrophilic β-sitosterol sugar esters were synthesized by a two-step biocatalytic approach using β-sitosterol vinyl adipate as an intermediate. The maximum conversion (above 90%) of β-sitosterol vinyl adipate was achieved using the saccharides glucose, sucrose, and raffinose. The chemical structure of the synthesized esters was confirmed by various techniques. The investigation of physical properties revealed that β-sitosterol sugar esters had enhanced water solubility (3.0-8.0 mM at 35 °C), reduced crystallinity, and high wettability. Their lyotropic liquid crystal properties were observed by polarized light microscopy. Furthermore, β-sitosterol sugar esters could be hydrolyzed into β-sitosterol adipate under simulated intestinal conditions at a low rate (2.83-18.14%). Most β-sitosterol sugar esters probably entered into intestinal bile salt micelles with ester bonds intact and showed up to 10-fold higher in vitro bioaccessibility than free β-sitosterol in non-fat systems. The excellent physical and functional characteristics of β-sitosterol sugar esters suggested their great potential application in the food industry.

Comprehensive utilization of sucrose resources via chemical and biotechnological processes: A review

Sucrose, one of the most widespread disaccharides in nature, has been available in daily human life for many centuries. As an abundant and cheap sweetener, sucrose plays an essential role in our diet and the food industry. However, it has been determined that many diseases, such as obesity, diabetes, hyperlipidemia, etc., directly relate to the overconsumption of sucrose. It arouses many explorations for the conversion of sucrose to high-value chemicals. Production of valuable substances from sucrose by chemical methods has been studied since a half-century ago. Compared to chemical processes, biotechnological conversion approaches of sucrose are more environmentally friendly. Many enzymes can use sucrose as the substrate to generate functional sugars, especially those from GH68, GH70, GH13, and GH32 families. In this review, enzymatic catalysis and whole-cell fermentation of sucrose for the production of valuable chemicals were reviewed. The multienzyme cascade catalysis and metabolic engineering strategies were addressed.