C. Anandharamakrishnan

Nanoencapsulation Techniques for Food Bioactive Components: A Review

The protection and controlled release of bioactive compounds at the right time and the right place can be implemented by encapsulation. Nanoencapsulation remains to be the one of the most promising technologies having the feasibility to entrap bioactive compounds. Nanoencapsulation of bioactive compounds has versatile advantages for targeted site-specific delivery and efficient absorption through cells. However, researches in the application of nanotechnology in the food industry have been very limited and there are only a few review articles that explored the nanoencapsulation technology. This review focuses on the various nanoencapsulation techniques such as emulsification, coacervation, inclusion, complexation nanoprecipitation, emulsification–solvent evaporation, and supercritical fluid for food ingredients. Drying techniques such as spray drying and freeze drying for stabilization of nanoparticles are also discussed. Current state of knowledge, limitations of these techniques, and recent trends are also discussed. Finally, safety and regulatory issues in the nanoencapsulation of bioactive compounds are also highlighted.

Techniques for Extraction of Green Tea Polyphenols: A Review

Tea is the second most consumed beverage all over the world after water. In recent times, tea has stretched the eyebrows of researchers and catching all the attention towards its health benefits. Tea has been proven beneficial by preventing the risk of some diseases like cancer and cardiovascular problems. Green tea is least processed and gives maximum benefits. The main components of the green tea are polyphenols which include the catechins, epicatechins, epigallocatechins, epicatechingallate, epigallocatechingallate, gallic acid, flavanoids, flavanols, and flavonols. Other than polyphenols, caffeine and theophylline are also present. Among which compounds of catechins family has been widely reported to have most beneficial effects on the health. Currently, the extraction of catechins is catching much higher attention and many techniques have been discovered and modified to extract these compounds. But very limited reviews have been reported discussing the impact of various techniques used for extraction of green tea polyphenols. This review focuses on various techniques employed for the extraction of polyphenols from green tea and other sources (pine bark, grape seed, and pomegranate) with their advantages and limitations. The current trends and future prospects are also highlighted.

Microencapsulation of Garcinia fruit extract by spray drying and its effect on bread quality.

BACKGROUND (-)-Hydroxycitric acid (HCA) is the major acid present in the fruit rinds of certain species of Garcinia. HCA has been reported to have several health benefits. As HCA is highly hygroscopic in nature and thermally sensitive, it is difficult to incorporate in foodstuffs. Hence, Garcinia cowa fruit extract was microencapsulated using three different wall materials such as whey protein isolate (WPI), maltodextrin (MD) and a combination of whey protein isolate and maltodextrin (WPI + MD) by spray drying. Further, these microencapsulated powders were evaluated for their impact on bread quality and HCA retention. RESULTS Maltodextrin (MD) encapsulates had higher free (86%) and net HCA (90%) recovery. Microencapsulates incorporated breads had enhanced qualitative characteristics and higher HCA content than water extract incorporated bread due to efficient encapsulation during bread baking. Comparatively, bread with MD encapsulates showed softer crumb texture, desirable sensory attributes with considerable volume and higher HCA content. CONCLUSION The higher HCA contents of encapsulate incorporated breads were sufficient to claim for functionality of HCA in bread. Comparatively, MD had efficiently encapsulated Garcinia fruit extract during spray drying and bread baking. Spray drying proved to be an excellent encapsulation technique for incorporation into the food system.

Challenges associated in stability of food grade nanoemulsions

ABSTRACT Food grade nanoemulsions are being increasingly used in the food sector for their physico-chemical properties towards efficient encapsulation, entrapment of bioactive compounds, solubilization, targeted delivery, and bioavailability. Nanoemulsions are considered as one of the important vehicles for the sustained release of food bioactive compounds due to their smaller size (nm), increased surface area, and unique morphological characteristics. Nanoemulsification is an ideal technique for fabricating the bioactive compounds in a nano form. Formation and stabilization of nanoemulsion depends on the physi-cochemical characteristics of its constituents including oil phase, aqueous phase, and emulsifiers. This review is mainly focused on the instability mechanisms of nanoemulsion such as flocculation, Ostwald ripening, creaming, phase separation, coalescence, and sedimentation. Further, the major factors associated with these instability mechanisms like ionic strength, temperature, solubilization, particle size distribution, particle charge, pH strength, acid stability, and heat treatment are also discussed. Finally, safety issues of food grade nanoemulsions are highlighted.

Computational Fluid Dynamics (CFD) Modeling for Bread Baking Process—A Review

Computational fluid dynamics (CFD) modeling of entire bread baking process is very complicated due to involvement of simultaneous physiochemical and biological transformations. Bread baking is a fickle process where composition, structure, and physical properties of bread change during the process. CFD finds its application in modeling of such complex processes. This paper provides the basics of CFD modeling, different radiation models used for modeling of heating in electrical heating ovens, modeling of bread baking process along with the predictions of bread temperature, starch gelatinization, and browning index. In addition, some recent approaches in numerical modeling of bread baking process are highlighted. Moreover, current limitations, recent developments, and future applications in CFD modeling of bread baking process are discussed in detail.

Synergistic radical scavenging potency of curcumin-in-β-cyclodextrin-in-nanomagnetoliposomes.

Curcumin is a highly potent nutraceutical associated with various health benefits. However, its hydrophobic nature affects its bioavailability and bioactivity, and limits nutraceutical applications. Drug-in-cyclodextrin-in-liposome has the ability to mask the hydrophobic nature of drug and achieve better encapsulation. Also, encapsulating iron oxide nanoparticles (IONPs) within liposomes endow additional beneficial functionalities of IONPs. In the present study, curcumin-β-cyclodextrin inclusion complex (IC) and IONPs were co-encapsulated within liposomes (curcumin-in-β-cyclodextrin-in-nanomagnetoliposomes) to achieve the synergistic antioxidant potential of curcumin and IONPs. IC of curcumin-β-cyclodextrin was prepared by a simple rapid method and successful inclusion was confirmed by Fourier transform infrared spectroscopy (FTIR) and nuclear magnetic resonance (NMR). Mean diameter of IONPs was found to be 180nm and X-ray diffraction pattern confirmed the formation of hematite nanoparticles. Band gap energy calculated using absorption spectra was 2.25eV, which falls in close proximity with the theoretically calculated values of hematite. Mean diameter of curcumin-in-β-cyclodextrin-in-nanomagnetoliposomes was 67nm and encapsulation efficiency of curcumin was found to be 71%. Further, the co-encapsulated particles possessed significantly low IC50 value (64.7791μg/ml, p<0.01) compared to conventional curcumin liposome and IONPs, indicating its synergistically enhanced radical scavenging property.

Influence of electrical and hybrid heating on bread quality during baking

Energy efficiency and product quality are the key factors for any food processing industry. The aim of the study was to develop energy and time efficient baking process. The hybrid heating (Infrared + Electrical) oven was designed and fabricated using two infrared lamps and electric heating coils. The developed oven can be operated in serial or combined heating modes. The standardized baking conditions were 18 min at 220°C to produce the bread from hybrid heating oven. Effect of baking with hybrid heating mode (H-1 and H-2, hybrid oven) on the quality characteristics of bread as against conventional heating mode (C-1, pilot scale oven; C-2, hybrid oven) was studied. The results showed that breads baked in hybrid heating mode (H-2) had higher moisture content (28.87%), higher volume (670 cm3), lower crumb firmness value (374.6 g), and overall quality score (67.0) comparable to conventional baking process (68.5). Moreover, bread baked in hybrid heating mode showed 28% reduction in baking time.

Bran-induced Effects on the Evolution of Bubbles and Rheological Properties in Bread Dough

Evolution of bubbles is the key to volume development in bread dough. The influence of wheat bran on bubble growth in bread dough through the mixing, fermentation, and proofing stages is described as a function of its level of addition. Confocal laser scanning microscopy in combination with image processing tools was used to obtain the bubble size and shape parameters. The relationship between bubble behavior and dough rheology was mapped using biaxial extension and dynamic oscillatory rheometry studies. With increase in level of bran addition, mean bubble size decreased corresponding to each stage and showed an inverse relationship with dough overpressure and elastic modulus. Addition of wheat bran was observed to suppress the bubble coarsening phenomenon in dough. Experimental observations indicated the plausibility of coalescence-mediated bubble growth in bread dough during the latter stages of fermentation and proofing, which was hindered in the presence of bran particles. PRACTICAL APPLICATION The results of this work provide an insight to the underlying mechanism by which wheat bran addition impacts the volume development in bread dough. The inferences presented in this research work can be used as a basis to study bubble dynamics in an opaque food system such as bread dough. This information would be of interest to industrial researchers working on the new product development of aerated bakery products with functional fibrous ingredients.

Impact of wheat bran addition on the temperature-induced state transitions in dough during bread-baking process

Wheat bran-mediated effects on temperature-induced state transitions of proofed bread dough were studied as function of its level of replacement (5%–15%) to wheat flour. Proofed dough was subjected to rheological tests at small deformations. During heating of proofed dough from 30 °C to 95 °C, the value of elastic modulus (G0) attained its maximum at a temperature (TG0 max ) that represented peak gelatinisation temperature (TP). Dough with 15% bran depicted significant increase in TP over other formulations. Bran addition increased glass transition temperature (Tg) of dough and suppressed drop in elastic modulus (G0) at T > Tg. The above events resulted in decreased loaf-specific volume and increased crumb hardness. The former was caused by retarded bubble expansion during initial stages of baking, explained by reduced uniaxial and biaxial extensibilities of dough. Mean bubble size depicted an inverse relationship with the hardness of breadcrumb.

Food-Grade Nanoemulsions for Protection and Delivery of Nutrients

Nanoemulsions are kinetically stable systems containing two immiscible liquids, water and oil, stabilized by a layer of surfactant material with droplet diameters in the nano range, of less than 200 nm. They are classified as oil-in-water, water-in-oil or multiple nanoemulsions, depending on the relative spatial organization of the oil and aqueous phases. Nanoemulsions find many applications in food systems such as protection and delivery of food bioactives, encapsulation and controlled release of flavor or antimicrobial compounds and preparation of low-fat food products. Further, the kinetic stability, optical transparency and unique rheological characteristics of nanoemulsions have a major role in formulation of beverage emulsions. Bioactive compounds such as curcumin, beta-carotene, resveratrol, catechins, omega-3-fatty acids and others, when encapsulated in nanoemulsions, possess increased stability, improved solubility, higher intestinal retention time due to mucoadhesive property and enhanced absorption via direct uptake from the gastrointestinal tract. Food grade, biocompatible nanoemulsions are economically and industrially viable for production by employing scalable top-down high energy approaches such as high pressure homogenization. Thus, the distinct advantages of nanoemulsions over conventional emulsions are the chief reasons behind the improved research and development efforts in the food industry. This chapter focuses on the high energy and low energy approaches for the fabrication of nanoemulsions, characteristics and advantages of nanoemulsions and their applications in the food industry.