Apple Fiber Research Articles

Comparison of Cholesterol Lowering Diets: Apple, Casein Cytochrom P450 protein and Cholesterol 7α Hydroxylase Activities in Hamsters

AbstractLithogenic diet, casein and apple fiber diets were fed to hamsters for 3-5 weeks. For control group, animals were fed on normal Purina chow without any supplement. The cholesterol lowering effect of lithogenic diet, casein and apple diets were compared. After dietary regimen, animals were screened for any gall stone formation. The isolated liver microsomes were separated from animals and tested for the cholesterol-7α Hydroxylase (CH) enzyme activity measurement in all three groups. The control animals did not show any gall stone formation and their CH enzyme activities were normal. The lithogenic diet showed significantly enhanced CH enzyme activities while animals fed on casein and apple diet regimen showed moderate increase in microsomal CH enzyme activity indicated cholesterol lowering in liver. In conclusion, cholesterol 7α hydroxylase may be a biomarker of cholesterol status in the body and microsomal CH enzyme may be lowered down after treatment of casein and apple diets.

Enrichment of ice cream with dietary fibre: Effects on rheological properties, ice crystallisation and glass transition phenomena

In the present study, the effects of four dietary fibre sources (oat, wheat, apple and inulin) on the rheological and thermal properties of model sucrose–polysaccharides solutions and ice cream mixes were investigated. The content of fibre in insoluble compounds increased significantly the viscosity and the shear thinning behaviour of the model solutions and ice creams, due to the increase of total solids and the formation of networks comprised of hydrated cellulose and hemicellulose. The increase of soluble material did not alter significantly the rheology of the samples but limited the freezing point depression and elevated the glass transition temperatures, indicating a potential cryoprotective action. The use of oat and wheat fibre favoured viscosity development due to water-binding, whereas inulin caused a remarkable increase of glass transition temperature (Tg) in model solutions and ice cream mixes, indicating the reduction of water molecule mobility from the bulk aqueous phase to the ice crystals’ surface. Apple fibre addition greatly increased viscosity and elevated the Tg values, particularly in the presence of proteins. Thus, our results suggest the potential use of dietary fibres as crystallisation and recrystallisation phenomena controllers in frozen dairy products.

Effects of incorporation of integral raw materials and dietary fibre on the selected nutritional and functional properties of biscuits

With the aim to develop nutritionally and functionally improved biscuits, standard wheat flour based recipe was supplemented with inulin (Raftilin) (10.5%) in combination with one of the following raw materials: soy flour, amaranth, carob (24.5%), apple fibre or oat fibre (16.5%). Various nutritional parameters such as proteins, fat, ash, carbohydrates total minerals, protein digestibility and energy value were determined in modified biscuits. Dietary fibre content, polyphenolic content and bioavailability and antioxidative activity were also assessed in the view of estimating the functionality of investigated samples. In order to evaluate the impact of technological procedure (baking) on analysed parameters, all experiments were conducted in dough samples as well. Supplementation with soy flour resulted in significant increase ( p < 0.05) in protein content and digestibility (from 10.04 to 14.49 mg/100 g and from 68.9% to 81.5%, respectively). The increase of total dietary fibre content in relation to the reference sample ranged from 30.9% (sample with amaranth) to 130.6% (sample enriched with oat fibre). Best results regarding total phenolic content and antioxidative activity were achieved by incorporation of carob and apple fibre into the reference sample. Supplementation with inulin resulted in significant decrease of the total energy value of modified biscuits (from 445 to 412 kcal/100 g dry matter).

Fruit‐based functional foods I: production of food‐grade apple fibre ingredients

SummaryWith the increased consumer interest in fibre‐enriched functional foods, industrial‐scale methods for functional fibre production are demanded. The development of a food‐grade fibre preparation method at lab scale that is feasible for industrial scale‐up is a pre‐requisite. This paper describes two lab‐scale fibre preparation methods that have potential to be scaled up to industrial setting for the production of fruit fibres containing desired bioactives and functionality. The two methods, one aqueous and the other ethanolic, were used to isolate fibres from Granny Smith apples (Malus domestica Borkh cv. ‘Granny Smith’). In the aqueous method, ground apple tissues were suspended in HEPES buffer (20 mM, pH 6.5), and then mechanically ruptured using an Ultra‐Turrax and ring grinder. Between steps, the cell‐wall materials were washed with the HEPES buffer. In the ethanolic method, ground apple tissues were stirred in 72% ethanol at 4 °C, filtered, re‐suspended in 72% ethanol and then washed. Microscopic examination and chemical analysis were performed on the resultant fibres. The aqueous method produced natural and uniform dietary fibres in the form of plant cell walls containing 0.282 g uronic acid per g dried fibre. By comparisons, the ethanolic method produced crude fibres containing only 0.182 g uronic acid per g dried fibre, the lower uronic acid content indicating the presence of impurities. Thus, the aqueous method appeared to be advantageous in terms of the retained pectic polysaccharide content and cost‐effectness for industrial scale‐up. Further characterisation using Folin‐Ciocalteu assay and high performance liquid chromatography indicates that the fibres obtained by the aqueous method contained significant amounts of phenolic compounds (2.6 mg catechin equivalent per g dried fibre). These results suggest that fibres obtained by the aqueous method may be more suitable for functional food applications where fibres with high pectic polysaccharide and beneficial phenolic antioxidants are preferred.

Physico-chemical properties of commercial fibres from different sources: A comparative approach

The lower intake of fibre and fibre-containing foods has refocused the food industry on the benefits of incorporating different fibres in the foodstuff. Nowadays, a whole range of fibres are available in the market, but sometimes a good choice becomes complicated due to their varied physico-chemical properties. In order to give some light when selecting fibres, a comparative study regarding some physical properties of commercial fibres from different sources is presented, with a view to increasing their use in food products, namely bakery products. Commercial fibres included in this study were hydroxypropylmethylcellulose, cellulose, locust bean gum, guar gum, inulin, galactooligosaccharides, oat and wheat fibres, and fibres extracted from apple and bamboo. Particle size distribution (PSD) of the dry commercial fibres ranged from around 10 to 334 μm; moreover PSD in wet (water and ethanol) form was also determined to have precise information about their behaviour when processing. Cereal fibres (oat 600 and wheat) exhibited the highest values for hydration properties (swelling, water holding and water binding capacity). Only the hydrocolloids (HPMC, locust bean gum and guar gum), with the exception of cellulose, yielded highly viscous solutions during the heating-cooling cycle; moreover oat 600 and apple fibre developed viscous solutions after cooling. HPMC, locust bean gum and guar gum significantly augmented the four SRC values, thus those hydrocolloids affected the relative contributions to water absorption of proteins, carbohydrates, damaged starch and pentosans. Fibre sources and degree of replacement significantly affected the SRC values for the four solvents in all the fibre groups, with the exception of lactic acid SRC in the case of cereal fibres. Differences in fibres effect on wheat flour quality can be easily detected by assessing solvent retention capacity, which can give information on the end use functionality of the wheat flour.

Apple Polyphenols and Fibers Attenuate Atherosclerosis in Apolipoprotein E-Deficient Mice

Atherosclerosis, which is closely linked to nutritional habits, is a major cause of mortality in Western countries. Most of the previous investigations carried out on health effects of apples have been focused on their capacity to lower lipid concentration as well as on their antioxidant effects. The aim of the present study was to investigate the antiatherosclerotic effects of apple polyphenols and fibers. A crude apple polyphenol extract and low-viscosity apple fibers isolated from cider apples were administered separately or in association with the diet of apo E-deficient mice. After 4 months of supplementation, lipemia and oxidative stress biomarkers were measured and atheroslerotic lesions assessed by histomorphometry. Total plasmatic cholesterol and triacylgycerol levels were not affected by supplementation, and hepatic cholesterol level was lower in the group supplemented with both fibers and polyphenols. Uric acid concentrations and antioxidant capacity (FRAP) in plasma were reduced in all groups supplemented with polyphenols or fibers. The mean lesion area was reduced by 17, 38, and 38%, respectively, for the polyphenol, fiber, and polyphenol + fiber groups. Apple constituents supplied at nutritional doses therefore limit the development of atherosclerotic lesions in the aorta of apo E-deficient mice. On the basis of the results, we hypothesize that apple fibers and polyphenols may play a role in preventing atherosclerosis disease by decreasing uric acid plasma level.

Dietary Fibers' Effect on the Textural Properties of Fish Heat-Induced Gels

ABSTRACT Fish heat-induced gels obtained from hake, containing one of five different dietary fibers (apple fiber, inner and outer pea fiber, chicory root oligofructose and inulin), were evaluated with respect to textural properties. Furthermore, the effect of different fiber product content (2 and 4%, w/w) on the same properties was investigated. The aim of this research was to produce a fish heat-induced gel product that could increase human fiber intake while retaining good texture properties. Addition of inner pea fiber to minced fish products–up to 4% (w/w)–was beneficial as the products retained their textural properties similar to those without any fiber. The fiber product containing chicory root inulins also generated positive results with the exception of its adverse effect on the product's hardness.

Thermal properties of extruded/injection‐molded poly(lactic acid) and biobased composites

AbstractTo determine the degree of compatibility between poly(lactic acid) and different biomaterials (fibers), poly(lactic acid) was compounded with sugar beet pulp and apple fibers. The fibers were added in 85 : 15 and 70 : 30 poly(lactic acid)/fiber ratios. The composites were blended by extrusion followed by injection molding. Differential scanning calorimetry and thermogravimetric analysis were used to analyze the extruded and extruded/injection‐molded composites. After melting in sealed differential scanning calorimetry pans, the composites were cooled through immersion in liquid nitrogen and aged (stored) at room temperature for 0, 7, 15, and 30 days. After storage, the samples were heated from 25 to 180°C at 10°C/min. The neat poly(lactic acid) showed a glass‐transition transition at 59°C with a change in heat capacity (ΔCp) value of 0.464. The glass transition was followed by crystallization and melting transitions. The enthalpic relaxation of the poly(lactic acid) and composites steadily increased as a function of the storage time. Although the presence of fibers had little effect on the enthalpic relaxation, injection molding reduced the enthalpic relaxation. The crystallinity percentage of the unprocessed neat poly(lactic acid) dropped by 95% after extrusion and by 80% for the extruded/injection‐molded composites. The degradation was performed in air and nitrogen environments. The degradation activation energy of neat poly(lactic acid) exhibited a significant drop in the nitrogen environment, although it increased in air. This meant that the poly(lactic acid) was more resistant to degradation in the presence of oxygen. Overall, injection molding appeared to reduce the activation energy for all the composites. Sugar beet pulp significantly reduced the activation energy in a nitrogen environment. In an air environment, both sugar beet pulp and apple fibers increased the activation energy. The enzymatic degradation of the composites showed a higher degradation rate for the extruded samples versus the extruded/injection‐molded composites, whereas the apple composites exhibited higher weight loss. The thermogravimetric analysis data showed that the degradation of unprocessed and extruded neat poly(lactic acid) followed a one‐step mechanism, whereas extruded/injection‐molded composites showed two‐step degradation. A higher fiber content resulted in up to three‐step degradation mechanisms. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2008

Texture and sensory properties of dairy desserts with dietary fibres of different sources

This study aims to evaluate dairy desserts with (11 g kg −1 ) and without dietary fibres by instrumental measurements of texture and colour and sensory analysis. To maintain a similar texture to that of commercial desserts without fibres, the composition of thickening (corn starch, xanthan and guar gums) and gelling (carrageenan) agents in the basic formulation was also studied. Dietary fibres of bamboo, inulin, wheat, apple, Psyllium and chitosan were tested. Sensory characteristics were evaluated by a non-trained panel. Appearance, flavour, texture and preference were scored using an unstructured line scale. Texture and surface colour were analysed by a Texture Analyser-xT2i and a tristimulus colourimeter (Minolta CR 300). Sensory attributes showed significant differences among treatments. The dessert with chitosan gave the lowest sensory scores. For stress at rupture, the dessert with Psyllium fibre showed the highest value, while the one with chitosan gave the lowest. Apple fibre led to a brownish colour. Panellists preferred inulin or bamboo desserts. Addition of inulin or bamboo fibres to dairy desserts is a good alternative to increase the daily intake of dietary fibres.

Fibres as carriers for Lactobacillus rhamnosus during freeze-drying and storage in apple juice and chocolate-coated breakfast cereals

The capability of different fibre preparations to protect the viability and stability of Lactobacillus rhamnosus during freeze-drying, storage in freeze-dried form and after formulation into apple juice and chocolate-coated breakfast cereals was studied. In freeze-drying trials wheat dextrin and polydextrose proved to be promising carriers for the L. rhamnosus strains: both freeze-drying survival and storage stability at 37 °C were comparable to the control carrier (sucrose). Using apple fibre and inulin carriers resulted in powders with fairly good initial freeze-drying survival but with poor storage stability at 37 °C. When fresh L. rhamnosus cells were added into apple juice (pH 3.5) together with oat flour with 20% β-glucan the survival of the cells was much better at 4 °C and at 20 °C than with sucrose, wheat dextrin and polydextrose, whereas with freeze-dried cells no protective effect of oat flour could be seen. The stability of freeze-dried L. rhamnosus cells at 20 °C was higher in chocolate-coated breakfast cereals compared to low pH apple juice. Similar to freeze-drying stability, wheat dextrin and polydextrose proved to be better carriers than oat flour in chocolate-coated breakfast cereals. Regardless of their differing capability to adhere to fibre preparations the two L. rhamnosus strains studied gave parallel results in the stability studies with different carriers.

Influence of dietary fiber addition on sensory and rheological properties of yogurt

The objective of this work was to study the effects of different dietary fibers on sensory and rheological properties of yogurts fortified with these fibers. Commercial fibers from apple, wheat, bamboo or inulin were used. Rheological characterization was performed by dynamic, shear and compression–extrusion assays. Storage time and type of fiber were significant factors for instrumental analysis. Syneresis and pH did not show any difference, while only apple fiber yogurt showed color differences compared to control. An untrained sensory panel analyzed consumer acceptability. Even though fibers modified certain rheological characteristics of the plain yogurt, the panelists awarded the supplemented yogurts scores indicating acceptability.

Effect of dietary fiber on morphine-induced constipation in rats.

Morphine is used to alleviate chronic cancer pain. However, constipation is a major adverse effect that often detracts from the patient's quality of life. In this study, we investigated the effectiveness of dietary fiber on morphine-induced constipation. Rats were fed on a normal diet or one containing either 10% or 20% apple fiber for two weeks before morphine was administered. In the control diet group, the fecal number and dry weight were decreased by treating with morphine in a dose-dependent manner. Moreover, the motility of the small and large intestines was reduced. The fecal number and weight were increased and the colon motility was promoted by dietary fiber, regardless of whether morphine was being administered. The dietary fiber increased the concentration of short-chain fatty acids (SCFAs) in the cecum. These results suggest that dietary fiber has a preventative effect on morphine-induced constipation by increasing SCFAs in the cecum, and thereby promoting colon motility in rats.

Changes in Content and Composition of Dietary Fiber in Yellow Onions and Red Delicious Apples During Commercial Storage

Changes in pectin composition and solubility are part of the softening process in apples during ripening and postharvest storage. Lignification may also occur with long-term storage. In the United States, apples and onions are harvested once yearly and then stored and marketed for the next 12 months. The changes that occur in the dietary fiber content and composition in Red Delicious apples and yellow Spanish onions during storage were studied, and the loss of fiber in peeled apples was determined. Dietary fiber was extracted by the enzymatic-chemical method of Theander and Westerlund. Storage had no effect on total or insoluble fiber content of apples; Klason lignin concentration was greater in samples stored for 12 months than in those stored for 0, 4, or 8 months. Peeling reduced apple fiber concentration about 25% by decreasing neutral and acidic sugars and Klason lignin in the insoluble fraction. The total fiber content of onions increased with storage, primarily by increasing the insoluble fiber content of uronic acids. The results suggest that the standardized, environmentally controlled storage of apples, as used in Washington State, has little effect on dietary fiber content. In contrast, the less rigorously controlled storage conditions for yellow Spanish onions increases the insoluble fiber fraction and uronic acid content.

Characteristics of pressurised pork meat batters as affected by addition of plasma proteins, apple fibre and potato starch

Characteristics of pressurised pork meat batters as affected by addition of plasma proteins, apple fibre and potato starch

Characteristics of pressurised pork meat batters as affected by addition of plasma proteins, apple fibre and potato starch

The authors thank the Comision Interministerial de Ciencia y Tecnologia (CICYT) for financial support under projects ALI97-0684 and ALI97-0759.

In-vitro mineral binding capacity of five fiber sources and their insoluble components for magnesium and calcium 1

In-vitro binding of calcium (Ca) and magnesium (Mg) by total dietary fiber, hemicellulose A (HCL A), lignocellulose (LCL), cellulose (CL), and lignin (L) fractions isolated from rice bran (RB), wheat bran (WB), oat fiber (OF), apple fiber (AF) and tomato fiber (TF) was evaluated. At pH 6.8, significant amounts of Ca were bound by whole fibers, ranging from 800 μg g −1 for RB to 10 097 μg g −1 for TF. Mg bound by whole fibers varied from 496 μg g −1 for OF to 2177 μg g −1 for WB. Re-acid washing (pH<2.0) released 95–99% of the Ca and Mg bound to the fibers. Fibers with the highest endogenous Ca and Mg concentrations bound significantly ( P<0.05) the highest amounts of the minerals studied. The Ca bound by HCL A varied from 9753 μg g −1 for RB to 11 337 mg g −1 for TF, whereas Mg bound varied from 1151 μg g −1 for OF to 5626 μg g −1 for TF hemicellulose fractions, respectively. Among the fiber components, Mg binding decreased in the order HCL A>LCL>L>CL, whereas Ca bound was in the order HCL A>LCL>CL>L. A relatively strong correlation was observed between the combined effects of protein content, hemicellulose, and lignin vs total Ca and Mg bound. 1998 Elsevier Science Ltd. All rights reserved

Dietary fibre composition in developing apple fruits

SummaryChanges in dietary fibre composition of ‘Delicious’, ‘Golden Delicious’, and ‘Stayman’ apples were studied over the course of fruit development. Fruit were analysed every 15 d starting 30 d after full bloom (DAFB) up to 150 DAFB in ‘Delicious’, 135 DAFB in ‘Golden Delicious’, and 120 DAFB in ‘Stayman’. Nonstarch cell wall materials (NSCWM) and nonstarch polysaccharides (NSP) content of apple flesh of all the cultivars decreased during development. During the period between 30 DAFB and 120 DAFB, NSP content of ‘Delicious’, ‘Golden Delicious’, and ‘Stayman’ fruit decreased by 25.2%, 29.0%, and 19.3%, respectively. Relative amount of monosaccharides present in apple fibre also changed during development. Proportions of rhamnose, arabinose, mannose, and galactose decreased during development while the proportions of xylose, glucose and uronic acid increased. Firmness of apple flesh was positively correlated with its NSP content. Firmness was also strongly correlated with the amounts of galactose, glucose, arabinose, mannose, and rhamnose present in the hydrolyzates of apple fibre.

Composition, Physico-chemical Properties and Enzymatic Degradation of Fibres Prepared from Different Tissues of Apple

Apple fibres from the tissue of three zones, namely epidermis, parenchyma and carpels zones, were prepared as nonoxidized and freeze-dried water-insoluble solid (WIS), oxidized and freeze-dried WIS, oxidized and oven-dried WIS, and nonoxidized and solvent-dried alcohol-insoluble solid. The yield and composition of the fibres, the characteristics of their soluble fraction, the enzymatic solubilization of the fibres and their hydration capacities were analysed. Oxidation led to a decrease in the amount of buffer-soluble pectin and to an increase of its hydrodynamic volume. It also decreased susceptibility to enzymatic solubilization and hydration capacities. Oven-drying, simulating industrial conditions, produced an important decrease of swelling capacity and enzymatic hydrolysis. Preparation of alcohol-insoluble solid led to higher fibre yield in all tissue zones but did not alter their properties.

Dietary fibre content of thirteen apple cultivars

Fibre composition of the following 13 apple cultivars was studied: ‘Cortland’, ‘Empire’, ‘Fuji’, ‘Golden Delicious’, ‘Gala’, ‘Granny Smith’, ‘Jonagold’, ‘Mutsu’, ‘McIntosh’, ‘Delicious’, ‘Rome’, ‘Stayman’ and ‘York’. Fruit samples from each of these cultivars were analysed for non-starch cell wall materials (NSCWM) and non-starch polysaccharides (NSP). NSCWM was further fractionated into soluble and insoluble fibre fractions. Both NSCWM and NSP content were found to be significantly influenced by cultivar. NSCWM content ranged from 19·1 g kg−1 apple flesh in ‘Fuji’ to 36·2 g kg−1 in ‘York’. Mean(±SD) NSCWM content of all the cultivars was 23·1±4·5 g kg−1. NSP content of apple flesh ranged from 13·8 g kg−1 in ‘McIntosh’ to 28·7 g kg−1 in ‘York’ with the overall mean for all cultivars being 17·9±4·2 g kg−1. Relative amount of monosaccharides found in the hydrolysates of apple fibre also varied among cultivars. The greatest difference was observed in galactose content. ©1997 SCI

Pineapple Shell as a Source of Dietary Fiber with Associated Polyphenols

Some properties of a high dietary fiber powder prepared from pineapple fruit shell were evaluated and compared to those of several commercial fruit fibers. Total dietary fiber (TDF) content (70.6%) was similar to some commercial dietary fibers from apple and citrus fruits; however, its sensory properties (neutral color and flavor) were better than those from commercial fibers above mentioned. The insoluble dietary fiber fraction amounted to 99% of the TDF. Major neutral sugars in soluble and insoluble dietary fiber were, respectively, xylose (36% of total sugar) and glucose (43% of total sugar). Total uronic acids (5.1%) and Klason lignin (11.2%) were also measured. Antioxidant activity (AA), a new property derived from the bioactive compounds associated with dietary fiber, was evaluated. At the concentration of 0.5 g of powdered sample/100 mL in the assay mixture, pineapple fiber showed a higher AA (86.7%) than orange peel fiber (34.6%), while commercial lemon and apple fibers did not exhibit any activit...