Dongxiao Sun-Waterhouse

Delivery of green tea catechin and epigallocatechin gallate in liposomes incorporated into low-fat hard cheese

The encapsulation of green tea catechin and epigallocatechin gallate (EGCG) in soy lecithin liposomes was examined at four concentrations (0%, 0.125%, 0.25% and 0.5% w/v), and inclusion in cheese at 0% and 0.25% w/v. The empty capsules had a mean diameter of 133nm and significantly (p<0.05) increased with the addition of catechin or EGCG. Electron microscopy revealed the lamellae and central core of the liposomes. Addition of antioxidants gave a significant (p<0.05) increase in the size of liposomes. Liposomes had surface potentials of -42.4 to -46.1mV with no significant difference between treatments, suggesting stable liposome systems. High efficiency (>70%) and yield (∼80%) were achieved from the incorporation of catechin or EGCG inside the liposome structure. Addition of either antioxidant increased the liposome phase transition temperature (>50°C). Nanocapsules containing these antioxidants were effectively retained within a low-fat hard cheese, presenting a simple and effective delivery vesicle for antioxidants.

Physicochemical Properties of Bread Dough and Finished Bread with Added Pectin Fiber and Phenolic Antioxidants

UNLABELLEDnComparative studies were conducted in this paper to investigate the effects of added dietary fiber (DF) and/or phenolic antioxidants on the properties of bread dough and finished bread. Breads were developed in the absence (control bread), or presence of apple pectin and/or fruit phenolic extracts (treated breads), and subjected to quality evaluation (attributes including color, weight, and volume) and characterization of chemical and rheological properties. Chemical analyses revealed that breads with added phenolic extracts had greater antioxidant activity and higher extractable phenolic content, than control bread and the treated breads with added apple pectin(s). The measured antioxidant activity was mainly derived from the phenolics present in bread. Storage modulus G (elasticity) and loss modulus G″ (viscocity) of the treated bread dough with added pectin(s) only were higher than those of control dough. The G or G″ of the treated breads incorporated with a combination of a pectin and fruit phenolic extract depended on the type of phenolic extract (that is, apple and blackcurrant extracts behaved differently from kiwifruit extract). The G and G″ at the final baking step were higher than those of other stages, indicating an increase in cross-linking among polymeric molecules and bread particles of high molecular weight. We conclude that the added pectin and/or phenolic extract had influenced bread dough cross-linking microstructure and bread properties through being involved in the interactions with bread components such as wheat proteins during dough development and bread baking.nnnPRACTICAL APPLICATIONnu2002 Dietary fibers and phytochemicals (including phenolic antioxidants) have long been recognized as the active nutrients responsible for the health benefits of fruit and vegetables to humans. Interest in incorporating bioactive ingredients such as dietary fiber and phenolic antioxidants into popular foods like bread has grown rapidly, due to the increased consumer health awareness. The added bioactive ingredients may or may not promote the development of bread dough. This paper reports the findings associated with the properties of the functional breads enhanced with apple pectin and apple, blackcurrant, and kiwifruit phenolic extracts. Results of this paper indicate that the success of the development of such functional breads is ultimately determined by the interactions among added bioactive ingredients and other bread components.

Spray-Drying Microencapsulation of Polyphenol Bioactives: A Comparative Study Using Different Natural Fibre Polymers as Encapsulants

This research explores the spray-drying microencapsulation of polyphenols (PPs), quercetin and vanillin, using four different fibre polymers as encapsulants (sodium alginate, methyl β-cyclodextrin (MβCD), hydroxypropylmethyl cellulose (HPMC) and inulin). The microstructure, physico-chemical properties, PP content and reconstitution properties in water of the spray-dried powders were systematically evaluated and compared. Techniques used for powder characterisation were scanning electron microscopy, N2 physisorption, Fourier transform infrared (FT-IR) spectroscopy and water activity measurements. High-performance liquid chromatography and viscosity measurements were used to characterise the solutions obtained by reconstitution of the spray-dried powders in methanol or water, respectively. Results show that the type of encapsulant strongly influenced powder morphology, powder surface area and encapsulation efficiency of PPs. Powders prepared using sodium alginate and MβCD possessed more spherical particle shape, smaller average particle size and higher specific surface area than those using HPMC or inulin as encapsulants. For each encapsulant, higher encapsulation efficiencies were achieved for vanillin (37–53xa0%) than quercetin (9–19xa0%). Encapsulation efficiencies were inulinu2009>u2009MβCDu2009>u2009HPMCu2009>u2009sodium alginate for vanillin-containing powders. Inulin, MβCD and sodium alginate all gave similar encapsulation efficiencies for quercetin-containing powders. All powders possessed low water activity and excellent dissolution properties in water. Therefore, spray-drying microencapsulation using natural fibre encapsulants is a feasible approach for delivering the dual health benefits of PPs and dietary fibre to consumers. Spray-drying yields a product in a convenient powder form, which can be reconstituted in water or other beverages for direct consumption or used as a functional additive in solid food systems.

Kiwifruit-based polyphenols and related antioxidants for functional foods: kiwifruit extract-enhanced gluten-free bread

The present study investigates the production of gluten-free bread enhanced with polyphenols and related antioxidants derived from a natural aqueous extract from green-fleshed kiwifruit (Actinidia deliciosa). Puree and four aqueous extracts, produced from ripe green kiwifruit in the absence of artificial preservatives, were subjected to storage stability trials at 4°C, 20°C and 38°C, and were chemically characterized (phenolic, vitamin C and pectic polysaccharide contents). The aqueous extract with good stability and high phenolic and vitamin C contents was used for gluten-free bread-making. The resultant kiwifruit extract-enhanced bread was acceptable to a taste panel, possessing softer and smoother texture than plain gluten-free bread. Thus, the aqueous extract of kiwifruit puree containing health-beneficial constituents can be considered a functional ingredient for gluten-free bread formulation.

Structure and Dynamics of Wheat Starch in Breads Fortified with Polyphenols and Pectin: an ESEM and Solid-State CP/MAS 13C NMR Spectroscopic Study

Two sets of breads formulated with a 20% difference in water quantity in the absence (control bread), or presence (fortified bread) of high methoxyl pectin (HM) and an apple, kiwifruit, or blackcurrant polyphenol (PP) extract (APE, KPE or BPE) were examined by Environmental Scanning Electron Microscopy (ESEM) and Cross Polarization/Magic Angle Spinning 13C NMR Spectroscopy. ESEM revealed that all the bread doughs had similar microstructures, comprising starch granules and yeast cells embedded in a continuous gluten matrix. However, the microstructure of the finished breads differed. NMR studies revealed differences in amylopectin-related crystalline domains and the amylose-related amorphous domains among the breads. All the breads showed V-type or amorphous starch structures by NMR, and the control bread may also contain some A-type starch. Breads formulated with 20% extra water showed a greater degree of starch gelatinization, a smoother crumb microstructure, and a lower amorphous starch content. It is feasible to incorporate PPs and pectin in breads at reasonably high concentrations.

Juices, Fibres and Skin Waste Extracts from White, Pink or Red-Fleshed Apple Genotypes as Potential Food Ingredients

This study measures and compares the bioactive content and appearance attributes of juices, dietary fibres (DFs) and skin wastes of three apple genotypes (white fleshed (WF), pink fleshed (PF) and red fleshed (RF)). The juices of the PF and RF apples had more appealing and stable colours and much greater total extractable polyphenol content (TEPC) (RF had the highest, 3.40xa0mg catechin equivalent/mL juice) and vitamin C (PF had the highest, 14.2xa0mg/100xa0mL juice), compared with the WF apple. DFs isolated from the three apples using aqueous and ethanolic methods varied in bioactive profiles as a function of genotype. The TEPC and antioxidant activity (AA) of the fibres decreased in the order of PF > RF > WF. The total DF (TDF) in the fibre obtained using the aqueous method decreased in the order of RFu2009>u2009PFu2009>u2009WF. The ethanolic method yielded higher neutral monosaccharide (NM) and slightly greater TDF contents than the aqueous method. More polyphenol species were detected in the PF fibres, especially those obtained using the aqueous method. The polyphenol content in the apple skin decreased in the order of RF > WF > PF, with PF having slightly more pectic polysaccharides. As a whole, the RF apple appeared to be the best genotype as the potential source for juice, fibre and skin waste extract (SWE) ingredients. The PF apple would be the second best genotype for juice and fibre ingredients. The skin of the RF and WF genotypes would provide a good source of polyphenols. There is potential for promoting RF and PF apple genotypes because of their excellent nutritional values. The aqueous fibre preparation method used herein containing no solvent treatment and freezing steps represents an industrial-scale cost-effective alternative to the conventional ethanolic methods used for producing DFs whilst retaining polyphenols.

No difference in fecal levels of bacteria or short chain fatty acids in humans, when consuming fruit juice beverages containing fruit fiber, fruit polyphenols, and their combination ☆

This study examined the effect of a Boysenberry beverage (750 mg polyphenols), an apple fiber beverage (7.5 g dietary fiber), and a Boysenberry plus apple fiber beverage (750 mg polyphenols plus 7.5 g dietary fiber) on gut health. Twenty-five individuals completed the study. The study was a placebo-controlled crossover study, where every individual consumed 1 of the 4 treatments in turn. Each treatment phase was 4-week long and was followed by a 2-week washout period. The trial beverages were 350 g taken in 2 doses every day (ie, 175 mL taken twice daily). The hypothesis for the study was that the combination of polyphenols and fiber would have a greater benefit on gut health than the placebo product or the fiber or polyphenols on their own. There were no differences in fecal levels of total bacteria, Bacteroides-Prevotella-Porphyromonas group, Bifidobacteriumspecies, Clostridium perfringens, or Lactobacillus species among any of the treatment groups. Fecal short chain fatty acid concentrations did not vary among treatment groups, although prostaglandin E2 concentrations were higher after consumption of the Boysenberry juice beverage. No significant differences were found in quantitative measures of gut health between the Boysenberry juice beverage, the apple fiber beverage, the Boysenberry juice plus apple fiber beverage, and the placebo beverage.