Fiber from fruit pomace: A review of applications in cereal-based products

Probiotic Bacteria Survival and Shelf Life of High Fibre Plant Snack - Model Study

The study aimed to develop plant-based model snacks that are high in fibre, contain probiotic bacteria and are convenient for long-term storage. The research focused on selecting a suitable form of probiotic bacteria (active biomass, microencapsulated, freeze-dried), inoculation method (in the base mass or in the filling of a snack) and appropriate storage conditions (4°Cor 20 °C). The potential synbiotic properties were evaluated. The microencapsulated bacteria had the highest survival rate at 4 °C, while the freeze-dried bacteria showed better survival rates at 20 °C. Probiotics had a higher survival rate when enclosed inside snacks with a low water activity (aw = 0.27) peanut butter filling than in snacks without filling (aw = 0.53). Enclosing the probiotics in a low aw filling ensures their survival at ambient temperature for 5 months at a count higher than 6 log CFU/g. The snacks exhibited high antioxidant capacity (average 300 mg ascorbic acid equivalent/100 g), polyphenol content (average 357 mg gallic acid equivalent/100 g) and high fibre content (average 10.2 g/100 g). The sensory analysis showed a high overall quality of the snacks (average 7.1/10 of the conventional units). Furthermore, after six months of storage, significant changes were observed in the antioxidant properties, polyphenol content and texture of the snacks, while their sensory quality remained unchanged. Moreover, a potential synbiotic effect was observed. The method used to assess bacterial growth indicated significantly higher values in the model snacks compared to a control sample. Therefore, this study has effectively addressed the gap in knowledge regarding the survival of probiotics in snacks of this nature.

Technological properties, shelf life and consumers' acceptance of high-fibre cookies prepared with juice processing by-products

High dietary fibre cookies were manufactured from non-wheat (triticale, spelt and rye) flours with apple, beetroot and pumpkin pomace powders added as natural colourants. Cookies were characterized by nutritional composition, colour, texture and sensory profile and subjected to a 2-month shelf-life study. Additionally, an acceptability study was done to determine consumers' acceptance of cookies. Cookies prepared from rye flour and pumpkin pomace, as well as cookies prepared from spelt flour and beetroot pomace, can be labelled as 'high fibre' (dietary fibre content of 8.90% and 7.09%, respectively), while cookies prepared from triticale flour and apple pomace can be labelled as a 'source of fibre' (dietary fibre content of 4.50%). No obvious trend in the colour of cookies was observed after storage at room temperature and 40 °C, indicating the stability of natural colourants. Hardness decrease was observed in all samples after storage; however, the acceptability study showed that consumers prefer softer cookies. Sensory analysis showed that there were no signs of rancidity in samples after storage. Although triticale flour and apple pomace sample received the highest liking scores for appearance, odour and taste, all samples had liking ratings higher than 4 (indifferent) and can be further modified to satisfy consumers' demands.

Trends and challenges of fruit by-products utilization: insights into safety, sensory, and benefits of the use for the development of innovative healthy food: a review

A significant portion of the human diet is comprised of fruits, which are consumed globally either raw or after being processed. A huge amount of waste and by-products such as skins, seeds, cores, rags, rinds, pomace, etc. are being generated in our homes and agro-processing industries every day. According to previous statistics, nearly half of the fruits are lost or discarded during the entire processing chain. The concern arises when those wastes and by-products damage the environment and simultaneously cause economic losses. There is a lot of potential in these by-products for reuse in a variety of applications, including the isolation of valuable bioactive ingredients and their application in developing healthy and functional foods. The development of novel techniques for the transformation of these materials into marketable commodities may offer a workable solution to this waste issue while also promoting sustainable economic growth from the bio-economic viewpoint. This approach can manage waste as well as add value to enterprises. The goal of this study is twofold based on this scenario. The first is to present a brief overview of the most significant bioactive substances found in those by-products. The second is to review the current status of their valorization including the trends and techniques, safety assessments, sensory attributes, and challenges. Moreover, specific attention is drawn to the future perspective, and some solutions are discussed in this report.

The characteristics of microwave-treated insoluble and soluble dietary fibers from grape and their effects on bread quality

This study investigated the morphological and hydration properties of untreated and microwave (MW)-treated isolate forms of soluble (SDF) and insoluble dietary fibers (IDF) obtained from grapes. Then, the rheological, textural, and other physical effects of the fibers (5% flour basis) were evaluated on bread quality. For this purpose, grape pomace was valorized as the juice extraction waste. MW significantly improved hydration properties of SDF and IDF by modifying their microstructures (p < .05). SDF had a clean-cut morphology whereas IDF had an indented microstructure with a wrinkled surface. After MW treatment, deep grooves and holes were observed. These variations in the IDF structure were more extensive. DF additions influenced water absorption, mixing tolerance index, dough development time, dough stability, resistance to extension, extensibility, energy of the dough and hardness, cohesiveness, springiness, chewiness, weight loss, specific volume, crust color difference of the bread in comparison with the properties of control samples significantly (p < .05). IDF had especially pronounced effects on the dough and bread characteristics. SDF enrichment provided more comparable results with the control bread than IDF. The originality of this work is to characterize isolated (100% purity) SDFs and IDFs, then discuss their effects on semi (dough) and final (bread) product quality.

Asparaginase Treatment of Sea Buckthorn Berries as an Effective Tool for Acrylamide Reduction in Nutritionally Enriched Wholegrain Wheat, Rye and Triticale Biscuits

Sea buckthorn pomace is a by-product of juice production, which is still rich in bioactive compounds. After drying, the pomace can be effectively used as a valuable addition to bakery products supporting their nutritional value. However, due to the high content of the amino acid asparagine in sea buckthorn, this promising material contributes to the undesirable formation of acrylamide. To reduce the risk from this potentially carcinogenic compound, enzymatic treatment of sea buckthorn with asparaginase was applied, which resulted in a substantial reduction of asparagine content from 1834 mg/kg in untreated dried sea buckthorn pomace to 89 mg/kg in enzymatically treated dried sea buckthorn pomace. 10% substitution of wholegrain cereal flour with enzymatically treated sea buckthorn pomace powder in rye and triticale biscuits resulted in a 35% reduction in acrylamide content, in the case of wholegrain wheat biscuits up to a 64% reduction, compared to biscuits with untreated sea buckthorn pomace powder. This study confirmed that treating fruit with asparaginase is an effective way to reduce health risk caused by acrylamide in biscuits enriched with nutritionally valuable fruit pomace.

Exploring modified rice flour and supplementation approach to enhance resistant starch content: Visco thermal and structural characterization

Supplementation of rice flour with Apple Pomace Powder (APP) and Synthetic Vinegar (SV) was investigated to reduce the glycemic potential of ready-to-eat snacks using extrusion cooking. The aim of the study was to compare the increase in resistant starch and decrease in glycemic index of modified rice flour based extrudates after supplementing the Modified rice flour with synthetic vinegar and apple pomace. The effects of independent variables-SV (3-6.5 %) and APP (2-23 %) were evaluated on resistant starch, predicted glycemic index, glycemic load, L*, a*, b*, ΔE and overall acceptability of supplemented extrudates. Design expert predicted 6 % SV and 10 % APP as desirable conditions for enhancement of resistant starch and reduction of glycemic index. Resistant Starch (RS) of supplemented extrudates increased by 88 % while as pGI and GL was decreased by 12 % and 66 % respectively as compared to un-supplemented extrudates. L* value increased from 39.11 to 46.78, a* value increased from 11.85 to 22.55, b* value increased from 10.10 to 26.22 and Δ E increased from 7.24 to 17.93 respectively in supplemented extrudates. The results suggested that apple pomace and vinegar can act in synergy to reduce the in-vitro digestibility of rice based snacks, while maintaining the sensory acceptance of the developed product. The significant (p < 0.001) decrease in the glycemic index was achieved as the supplementation level increased. The increase in RS correlates with the decrease in glycemic index and glycemic load.

Sustainability on Bread: How Fiber-Rich Currant Pomace Affects Rheological and Sensory Properties of Sweet Fat-Based Spreads

Dietary fiber may contribute to increasing the nutritional value of “unhealthy food”—for instance, spreads with high fat and sugar content. The high amount of fiber and the presence of phenolic compounds, organic fruit acids, and aroma compounds make currant pomace a promising ingredient to be used in a wide range of foods. However, the particle size of this by-product is a key factor influencing texture, rheology, physical stability, and sensory properties of the final commodities. Wet planetary ball milling of seedless currant pomace suspended in oil resulted in particles <30 µm, which is required for a creamy texture. Spread stiffness and viscosity were adapted by lowering the solid fat content in a way that the fruity spreads with 16 g/100 g pomace resembled a sweet commercial nut spread. The pomace showed stabilizing effects, as oil separation was reduced and a viscosity increase during storage was prevented. Principal component analysis after sensory flash profiling of five formulations highlighted differences in fruitiness, sweetness, greasiness, and viscosity. Hence, depending on the pomace level and fat composition in the formulation, the properties of sweet spreads can be specifically designed to fulfill the respective requirements. Additionally, sweet and savory wafer fillings provide great potential to be enriched with fruit pomace.

Effect of different fibre addition on cookie dough and texture

Different commercial fibres from bamboo (BAM), cocoa (COC), psyllium (PSY), chokeberry (ARO) and citrus (CIT) were characterized for technological (oil- and water-holding capacity, solubility and bulk density) and physical (moisture, colour and particle size) features and added to a cookie recipe. The doughs were prepared using sunflower oil and white wheat flour was substituted with 5% (w/w) of the selected fibre ingredient. The attributes of the resulting doughs (colour, pH, water activity and rheological tests) and cookies (colour, water activity, moisture content, texture analysis and spread ratio) were compared to control doughs and to cookies made with refined flour and whole flour formulation. The selected fibres consistently impacted dough rheology and, consequently on, the spread ratio and the texture of the cookies. While the viscoelastic behaviour of the control dough made with refined flour was maintained in all sample doughs, adding fibre decreased loss factor (tan δ), except for ARO-added dough. Substitution of wheat flour with fibre decreased the spread ratio except for the PSY addition. The lowest spread ratio values were observed for CIT-added cookie, which were similar to whole flour cookies. The addition of phenolic-rich fibres positively affected the in vitro antioxidant activity of the final products.

Polyphenol-Dietary Fiber Conjugates from Fruits and Vegetables: Nature and Biological Fate in a Food and Nutrition Perspective

In the past few years, numerous studies have investigated the correlation between polyphenol intake and the prevention of several chronic diseases. Research regarding the global biological fate and bioactivity has been directed to extractable polyphenols that can be found in aqueous-organic extracts, obtained from plant-derived foods. Nevertheless, significant amounts of non-extractable polyphenols, closely associated with the plant cell wall matrix (namely with dietary fibers), are also delivered during digestion, although they are ignored in biological, nutritional, and epidemiological studies. These conjugates have gained the spotlight because they may exert their bioactivities for much longer than extractable polyphenols. Additionally, from a technological food perspective, polyphenols combined with dietary fibers have become increasingly interesting as they could be useful for the food industry to enhance technological functionalities. Non-extractable polyphenols include low molecular weight compounds such as phenolic acids and high molecular weight polymeric compounds such as proanthocyanidins and hydrolysable tannins. Studies concerning these conjugates are scarce, and usually refer to the compositional analysis of individual components rather than to the whole fraction. In this context, the knowledge and exploitation of non-extractable polyphenol-dietary fiber conjugates will be the focus of this review, aiming to access their potential nutritional and biological effect, together with their functional properties.

From food waste to functional component: Cashew apple pomace

Globally, large numbers of people suffer from undernourishment and food insecurity, while a third of food produced is lost or wasted. The widely cultivated cashew nut produces large quantities of waste in early processing. It grows on an edible peduncle called the cashew apple which contains many essential nutrients. An estimated 36.9 million tons of cashew apples are produced annually, but only small amounts are used to make juice. The remainder is considered production waste. This review presents the potential of cashew apple pomace as a food ingredient and examines the effects of incorporation on chemical composition, physical properties and sensory evaluation. Inclusion in optimized amounts into food products is a strategy proven to produce palatable results with high acceptability. Transforming this manufacturing by-product into a functional food component will have economic benefits, improve resource-utilization, promote sustainability and potentially increase the nutritional value of foods.

Papaya dietary fiber concentrates for providing functionality to muffin formulations

BACKGROUND

Papaya leftovers are a good source of dietary fiber (DF) and antioxidants. They can be transformed in dietary fiber concentrates (DFCs) to be used as ingredients in food formulation, improving consumers' health status.

RESULTS

Using the peel or the pulp of papaya, DFCs were produced. These DFCs were used in muffin production. Muffins produced with 7.7% DFCs and 47.6 g water had the same specific volume (2.0 cm³  g^-1 ) but softer crumb than those obtained with a reference formulation without DF addition, showing average hardness of 15 N. In general, the addition of DFCs of pulp or peel slightly affected other textural profile parameters. Also, non-significant differences were observed for muffins containing pulp or peel DFCs, which showed average values of 10.9 N for chewiness, 0.95 for springiness, 0.76 for cohesiveness and 0.42 for resilience. Regarding the crumb structure, muffins with pulp DFCs showed the lowest value for d_3.2 (1.3 ± 0.3 mm). Meanwhile, the highest anti-radical and reducing capacity, 240 ± 2 and 1050 ± 6 mgeq Trolox g^-1 muffin (dry basis), respectively, were observed in the muffins with peel DFC. Finally, the addition of DFCs allowed us to maintain lower hardness values than those of the reference formulation during the whole storage period studied (22 days). Muffins with peel DFCs tended to have a lower rate of crumb hardening (0.08 ± 0.02) d^-1 .

CONCLUSION

The addition of papaya DFCs to muffin formulations confers interesting properties for industry and consumers, providing functionality, extending the shelf life as well as transforming papaya leftovers in new functional ingredients, contributing to a circular economy. © 2022 Society of Chemical Industry.

Evaluation of the Amazonian fruit Ambelania acida: Chemical and nutritional studies

Ambelania acida is native to the Amazon region, with few published studies of its fruits. We examined the proximate composition of its fruits, including minerals, fatty acids, volatile organic compounds (VOCs), as well as its antioxidant capacity. The protein contents (2.61%) of the pulp and seeds (13.6%) were higher than observed in other taxa of the family or in other tropical fruits. Peel and pulp showed high contents of potassium, calcium, and magnesium, and the potassium content in the pulp was 1125 mg/100 g. The peel had higher contents of total phenolics, tannins, and ortho-diphenols than the pulp, as well as better antioxidant activity as evidenced by 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), 1,1-diphenyl-2-picrylhydrazyl (DPPH), Ferric Reducing Antioxidant Power (FRAP), and Fe²⁺ chelating activity assays. GC-MS analyses identified 42 VOCs in the peel and pulp, with more than 90% being classified as terpenes. Eleven types of fatty acids were identified in the lipid fractions of the peel, pulp, and seeds. Linoleic acid, an essential fatty acid for humans, was the principal fatty acid in the edible portion of the fruit, therefore, evidencing its nutritionally significant profile for the fruits when considering the relationship among polyunsaturated, saturated, and monounsaturated fatty acids. The information gathered here indicates that this native fruit is a healthy food source and its cultivation and consumption should be stimulated.

Chemical and nutritional characterization of Ambelania duckei (Apocynaceae) an unexplored fruit from the Amazon region

Ambelania duckei Markgr is a species of the Apocynaceae family, native to the Amazon region that is unexplored from a nutritional point of view and studied in relation to its chemical constituents. This work presents an unprecedented study of the proximate composition, lipid profile, a chromatographic analysis, and the antioxidant activity of extracts obtained from the pulp, peel and seeds of the fruit. The results showed that potassium, calcium, and magnesium stood out as the most abundant key minerals in the fruit peel and pulp, with an emphasis on the potassium present in the fruit pulp at 1750.0 mg/100 g. The peel had the highest content of total phenolics (374.86 mg/g), flavonoids (15.54 mg/g), tannins (27.45 mg/g) and O-diphenols (379.36 mg/g; 645.71 mg/g). The antioxidant activity (AA) was highest in the peel compared to the pulp in the DPPH, ABTS, and ORAC tests showing: IC₅₀ of 29.82; 43.67; and 407.13 µg/mL, respectively but a lower activity for the Fe²⁺ chelator. The analysis of the lipid fractions from the peel, pulp, and seeds of the A. duckei fruit resulted in 14 types of fatty acids. The major fatty acids found in the three parts of the fruit were oleic acid (peel, 22.52 %), palmitic acid (pulp, 17.34 %), and linoleic acid (seeds, 47.99 %). The lipid profile and nutritional aspects had a PUFA/SFA ratio (0.4-1.8) in the different parts of the A. duckei fruit; the atherogenic and thrombogenic indexes were higher in the peel (1.23) and pulp (0.62), respectively. The ratio between the hypocholesterolemic and hypercholesterolemic fatty acids (0.5 - 3.8) calculated for the fruit are within the desirable range for a nutritious food. The chromatographic analysis of the volatile organic compounds (VOCs) from the peel and pulp of the fruit, identified 74 VOCs, of which 60.9 % are related to terpenes, and emit notes such as cucumber, green, fatty, floral, and mint, due to the presence of substances with OAVs > 10, especially α-ionone, 1,8-cineole, 2,4-decadienal, and dodecanal. The analysis of the MS and MS/MS spectra of the chromatograms obtained by LC- QTOF-HRMS led to the identification of 26 compounds in the peel, seeds and pulp of A. duckei, such as fatty acids, phenolic acid, flavonoids, proanthocyanidins, alkaloids, and terpenoids. The results show that the pulp of A. duckei has potential as nourishing food and the nutritional and chemical aspects of the peel can be applied to commercial applications.

Sorption Isotherms, Glass Transition and Bioactive Compounds of Ingredients Enriched with Soluble Fibre from Orange Pomace

Citrus fruits are one of the main crops worldwide. Its industrialization, primarily juice production, produces large amounts of byproducts, composed of seeds and peels, that can be used to obtain new ingredients. In this study, sorption behaviour, glass transition, mechanical properties, colour and bioactives of four different soluble fibre-enriched powders obtained from orange pomace using green technologies were studied. Powders were equilibrated at water activities between 0.113 and 0.680 for fifteen weeks at 20 °C, and studies were performed to indicate the best storing conditions to ensure the glassy state of the amorphous matrix and higher bioactive stability. By combining the Gordon and Taylor model with the Henderson isotherm, the critical water activity and content for storage in a glassy state were determined. The ingredient obtained after extrusion + hot water is the most stable, which is also the one with the highest dietary fibre content. Powder obtained by jet cooking is the least stable, as it is not in a glassy state at any water activity at room temperature. To increase storage stability, these should be stored at refrigeration temperatures.

Development of Bread Dough by Sheeting: Effects of Sheeting Regime, Bran Level and Bran Particle Size

The effects of sheeting on bread dough development and baked loaf quality were investigated, using Dynamic Dough Density and springback to quantify development, and examining effects of the sheeting regime on bread quality in terms of loaf volume and crumb structure. Bread doughs, with and without bran at different levels and particle sizes, were formed through a short mixing period, then sheeted through a benchtop manual sheeter at roll gaps of 6, 9 and 12 mm for different numbers of sheeting passes. The sheeting of doughs without bran increased dough expansion and baked loaf volume up to 12 sheeting passes. Loaves were larger after sheeting at a 6 mm roll gap, reflecting the greater gluten development at the smaller gap, although the crumb structure was less fine, with fewer gas cells and larger average gas cell diameters. The addition of bran decreased dough expansion and loaf volumes, with Fine bran and Coarse bran both more damaging than Medium bran, indicating the opportunity to optimise bran particle size to maximise bread quality. Sheeting was effective in alleviating the damaging effects of bran, with sheeting for 8 passes giving more dough expansion, larger loaf volumes and finer crumb structures than sheeting for 12 passes, indicating an even more damaging effect of bran when gluten is overstretched by sheeting. The work demonstrates the opportunity to enhance bread quality, particularly of healthy high-fibre breads, by employing sheeting to enhance gluten development and to offset the damage to gluten caused by the presence of bran.

Biomolecules from Plant Wastes Potentially Relevant in the Management of Irritable Bowel Syndrome and Co-Occurring Symptomatology

During and following the processing of a plant’s raw material, considerable amounts are wasted, composted, or redistributed in non-alimentary sectors for further use (for example, some forms of plant waste contribute to biofuel, bioethanol, or biomass production). However, many of these forms of waste still consist of critical bioactive compounds used in the food industry or medicine. Irritable bowel syndrome (IBS) is one of the most common functional gastrointestinal disorders. The primary treatment is based on symptomatology alleviation and controlled dietary management. Thus, this review aimed to describe the possible relevance of molecules residing in plant waste that can be used to manage IBS and co-occurring symptoms. Significant evidence was found that many forms of fruit, vegetable, and medicinal plant waste could be the source of some molecules that could be used to treat or prevent stool consistency and frequency impairments and abdominal pain, these being the main IBS symptoms. While many of these molecules could be recovered from plant waste during or following primary processing, the studies suggested that enriched food could offer efficient valorization and prevent further changes in properties or stability. In this way, root, stem, straw, leaf, fruit, and vegetable pomaces were found to consist of biomolecules that could modulate intestinal permeability, pain perception, and overall gastrointestinal digestive processes.

The food industry by-products in bread making: single and combined effect of carob pod flour, sugar beet fibers and molasses on dough rheology, quality and food safety

Obtaining high-quality value-added bread with extended shelf-life by utilizing food industry by-products that would have minimal negative effect on gluten structure while avoiding the usage of synthetic preservatives, was the challenge of this study. For this purpose the influence of the combination of carob pod flour (C, 0-15%), sugar beet fibers (F, 0-10%) and sugar beet molasses (M, 0-6%) on dough rheology and bread quality was investigated. Selected materials were of good microbiological quality, while carob flour and sugar beet fibers were rich in dietary fibers (43.6% and 67.0%, respectively). The presence of high share of dietary fibers (combination of C and F) increased dough resistance to extension up to 2.5 times, while dough extensibility was reduced by 50%. The addition of molasses had less pronounced single effect on dough properties however its impact in combination with fiber-rich materials outweighed the individual effect (an increase of dough resistance at about 55%). Molasses alone and in combination with other ingredients had positive effect on bread quality. Sample M₆F₅ attained crumb quality score (6.0 of maximum 7.0) higher than in control sample (5.6). High share of C and F reduced loaf volume and crumb quality of bread up to 56% and 50%, respectively and increased hardness 7.5 times. However, carob flour (7.5%) increased polyphenols content and antioxidant capacity 3 and 4 times, respectively. Moreover, carob flour and molasses and their combination showed inhibitory effect on mold mycelia growth and spores formation. Regarding all of the above, C_7.5M₃F₅ was chosen as optimal sample.

Valorization of by-products from Prunus genus fruit processing: Opportunities and applications

Food processing, especially the juice industry, is an important sector that generate million tons of residues every. Due to the increasing concern about waste generation and the interest in its valorization, the reutilization of by-products generated from the processing of popular fruits of the Prunus genus (rich in high-added value compounds) has gained the spotlight in the food area. This review aims to provide an overview of the high added-value compounds found in the residues of Prunus fruits (peach, nectarine, donut peach, plum, cherry, and apricot) processing and applications in the food science area. Collective (pomace) and individual (kernels, peels, and leaves) residues from Prunus fruits processing contains polyphenols (especially flavonoids and anthocyanins), lipophilic compounds (such as unsaturated fatty acids, carotenes, tocopherols, sterols, and squalene), proteins (bioactive peptides and essential amino acids) that are wasted. Applications are increasingly expanding from the flour from the kernels to encapsulated bioactive compounds, active films, and ingredients with technological relevance for the quality of bread, cookies, ice cream, clean label meat products and extruded foods. Advances to increasing safety has also been reported against anti-nutritional (amygdalin) and toxic compounds (aflatoxin and pesticides) due to advances in emerging processing technologies and strategic use of resources.

Strategies to Increase the Value of Pomaces with Fermentation

The generation of pomaces from juice and olive oil industries is a major environmental issue. This review aims to provide an overview of the strategies to increase the value of pomaces by fermentation/biotransformation and explore the different aspects reported in scientific studies. Fermentation is an interesting solution to improve the value of pomaces (especially from grape, apple, and olive) and produce high-added value compounds. In terms of animal production, a shift in the fermentation process during silage production seems to happen (favoring ethanol production rather than lactic acid), but it can be controlled with starter cultures. The subsequent use of silage with pomace in animal production slightly reduces growth performance but improves animal health status. One of the potential applications in the industrial context is the production of enzymes (current challenges involve purification and scaling up the process) and organic acids. Other emerging applications are the production of odor-active compounds to improve the aroma of foods as well as the release of bound polyphenols and the synthesis of bioactive compounds for functional food production.

Incorporation of polyphenols in baked products

Bakery foods, including breads, cakes, cookies, muffins, rolls, buns, crumpets, pancakes, doughnuts, waffles, and bagels, etc., have been an important diet of humans for thousands of years. As the nutraceuticals with various biological activities, polyphenols, especially polyphenol-enriched products are widely used in bakery foods. The polyphenol-enriched products are mainly from fruits and vegetables, including fruits in whole, juice, puree, jam, and the powder of dried fruits, pomace, and peels. Incorporation of these products not only provide polyphenols, but also supply other nutrients, especially dietary fibers for bakery products. This chapter discussed the thermal stability of different types of polyphenols during baking, and the effect of polyphenols on the sensory attributes of baked foods. Moreover, their role in mitigation of reactive carbonyl species and the subsequent formation of advanced glycation end products, antioxidant and antimicrobial activities have been also discussed. Since polyphenols are subjected to high temperature for dozens of minutes during baking, future works need to focus on the chemical interactions of polyphenols and their oxidized products (quinones) with other food components, and the safety consequence of these interactions.

Addition of Orange Pomace Attenuates the Acute Glycemic Response to Orange Juice in Healthy Adults

BACKGROUND

Fiber is an important part of a healthy diet and is known to attenuate postprandial glycemia. Orange pomace (OP) is a by-product of orange juice (OJ) production and is a rich source of fiber.

OBJECTIVE

Two separate studies determined the impact of added OP to 100% OJ on postprandial glycemic response compared with sugar-matched OJ or whole orange fruit (WOF).

METHODS

Study 1 included 17 adults [65% female, age 39.3 ± 3.1 y, and BMI (in kg/m2) 24.6 ± 0.7], and study 2 included 45 different adults (47% female, age 25.1 ± 4.3 y, and BMI 22.5 ± 1.6). Studies were conducted at separate locations using a randomized, 3-arm, crossover design to test the glycemic response to sugar-matched OJ, OJ with 5 g fiber from OP (OPF), or WOF. The primary outcomes were 2-h glucose incremental area under the curve (iAUC) in study 1, analyzed by repeated measures ANOVA, and maximum glucose concentration (Cmax) in study 2, analyzed using PROC MIXED (ANCOVA). Glucose and insulin concentrations were measured at fasting and multiple time points over 2 h after test product consumption (study 1, serum; study 2, plasma).

RESULTS

In study 1, glucose iAUC was not significantly lower in OPF compared to the OJ or WOF (825 ± 132 compared with 920 ± 132 and 760 ± 132 mg · min · dL-1, respectively, P = 0.57 for both). In study 2, glucose iAUC was significantly lower in WOF compared with OPF and OJ (689 ± 70.7 compared with 892 ± 70.7 and 974 ± 70.7 mg · min · dL-1, P = 0.02 and 0.001, respectively). Data from both studies indicated OPF reduced Cmax compared with OJ and that the reductions were comparable to WOF (study 1: OPF, 115 ± 4.06 compared with OJ, 124 ± 4.06 and WOF, 114 ± 4.06 mg · dL-¹, P = 0.002 and 0.75, respectively; study 2: OPF, 128 ± 1.92 compared with OJ, 136 ± 1.92 and WOF, 125 ± 1.92 mg · dL-¹, P = 0.001 and 0.28, respectively).

CONCLUSION

Data from both studies demonstrated no significant effect of OPF on postprandial iAUC compared with OJ. However, adding OP into OJ attenuates the postprandial glucose Cmax, and the responses were comparable to WOF in healthy adults.

Application of Crude Pomace Powder of Chokeberry, Bilberry, and Elderberry as a Coloring Foodstuff

Berry pomace, rich in polyphenols, especially anthocyanins, accumulates during the production of red juices. Pomace from chokeberry (Aronia melanocarpa Michx.), bilberry (Vaccinium myrtillus L.), and elderberry (Sambucus nigra L.) represent good sources of coloring foodstuffs. Pomace powders (PP) were prepared by milling the seedless fractions of the three dried berry pomaces (50 °C, 8 h). Techno-functional properties of the powders such as particle size distribution, bulk density, sedimentation velocity, and swelling capacity were determined to evaluate the powders for possible food applications. Total anthocyanin content was quantified by UHPLC-DAD before and during a storage experiment to monitor the degradation of anthocyanins in the PP and in a yogurt model application. The high content of phenolic compounds and the still intact cell structure ensured high stability of anthocyanins over 28 days of storage. In the model application, color saturation was stable over the whole storage time of 14 days. Regarding the techno-functional properties, only a few differences between the three PP were observed. The particle size of elderberry PP was larger, resulting in lowest bulk density (0.45 g/mL), high cold-water solubility (16.42%), and a swelling capacity of 10.16 mL/g dw. Sedimentation velocity of the three PP was fast (0.02 mL/min) due to cluster formation of the particles caused by electrostatic and hydrophobic properties. Compared to other high-intensity coloring foodstuffs, the use of PP, showing acceptable color stability with potential health-promoting effects, represents a wide applicability in different food applications and especially in products with a longer shelf-life.

Valorized Food Processing By-Products in the EU: Finding the Balance between Safety, Nutrition, and Sustainability

Food businesses in the European Union are preparing for a carbon-neutral future by gradually transitioning to a circular way of operating. Building upon results from the EU REFRESH project, we consider the most valuable food processing by-streams in Europe and discuss potential food safety risks that must be considered while valorizing them for human consumption. These risks are weighed against the nutritional benefits offered by these products and their potential applications in food supply chains. Broadly, we examine whether it is possible for spent grains, cheese whey, fruit and vegetable scraps, meat processing waste, and oilseed cakes and meals to be safe, sustainable, and nutritionally valuable at the same time. The discussion highlights that valorizing by-products obtained from food processing operations is feasible on a large scale only if consumers deem it to be a safe and acceptable practice. Extracting valuable compounds from by-products and using them in the preparation of functional foods could be a way to gain consumer acceptance. Furthermore, we find that current EU food safety legislation does not sufficiently accommodate food processing by-products. A way to bridge this regulatory gap could be through the adoption of private food safety standards that have shown proclivity for sustainability-related issues in food supply chains. Finally, by proposing a decision tree, we show that it is indeed feasible for some food processing by-products to be valorized while ensuring sustainability, food safety, and nutritional relevance.

Green extraction techniques from fruit and vegetable waste to obtain bioactive compounds-A review

Food wastes imply significant greenhouse gas emissions, that increase the challenge of climate change and impact food security. According to FAO (2019), one of the main food wastes come from fruit and vegetables, representing 0.5 billion tons per year, of the 1.3 billion tons of total waste. The wastes obtained from fruit and vegetables have plenty of valuable components, known as bioactive compounds, with many properties that impact positively in human health. Some bioactive compounds hold antioxidant, anti-inflammatory, and anti-cancer properties and they have the capacity of modulating metabolic processes. Currently, the use of fruit and vegetable waste is studied to obtain bioactive compounds, through non-conventional techniques, also known as green extraction techniques. These extraction techniques report higher yields, reduce the use of solvents, employ less extraction time, and improve the efficiency of the process for obtaining bioactive compounds. Once extracted, these compounds can be used in the cosmetic, pharmaceutical, or food industry, the last one being focused on improving food quality.

Extrusion Processing of Pure Chokeberry (Aronia melanocarpa) Pomace: Impact on Dietary Fiber Profile and Bioactive Compounds

The partial substitution of starch with dietary fiber (DF) in extruded ready-to-eat texturized (RTE) cereals has been suggested as a strategy to reduce the high glycemic index of these food products. Here, we study the impact of extrusion processing on pure chokeberry (Aronia melanocarpa) pomace powder (CPP) rich in DF and polyphenols (PP) focusing on the content and profile of the DF fractions, stability of PP, and techno-functional properties of the extrudates. Using a co-rotating twin-screw extruder, different screw speeds were applied to CPP with different water contents (cw), which resulted in specific mechanical energies (SME) in the range of 145-222 Whkg-1 and material temperatures (TM) in the range of 123-155 °C. High molecular weight soluble DF contents slightly increase with increasing thermomechanical stress up to 16.1 ± 0.8 g/100 g dm as compared to CPP (11.5 ± 1.2 g/100 g dm), but total DF (TDF) contents (58.6 ± 0.8 g/100 g dm) did not change. DF structural analysis revealed extrusion-based changes in the portions of pectic polysaccharides (type I rhamnogalacturonan) in the soluble and insoluble DF fractions. Contents of thermolabile anthocyanins decrease linearly with SME and temperature from 1.80 ± 0.09 g/100 g dm in CPP to 0.24 ± 0.06 g/100 g dm (222 Whkg-1, 155 °C), but phenolic acids and flavonoids appear to be largely unaffected. Resulting techno-functional (water absorption and water solubility) and physical properties related to the sensory characteristics (expansion, hardness, and color) of pure CPP extrudates support the expectation that granulated CPP extrudates may be a suitable food ingredient rich in DF and PP.

Effects of orange peel powder on rheological properties of wheat dough and bread aging

Orange peels, the major byproduct of orange fruit processing, are a good material for functional food production because of their excellent physiological and health function. The effects of orange peel powder (OPP) on the rheological and reho-fermentation properties of high-gluten wheat dough and bread staling were investigated. The results showed that OPP significantly modified wheat dough characteristics and bread quality for its fiber, pectin and polyphenol content. Incorporation of OPP in wheat dough mainly caused competitive water absorption. It improved dough water absorption from 59.70% to 66.82% by increasing the development time (from 1.40 min to 4.51 min) and decreasing the retrogradation degree (from 1.01% to 0.68%) at a low content (no more than 5%) but showed adverse effects at higher content because of stronger gluten-dilution action than excessive water sequestration of OPP. It strengthened the dough elasticity by increasing the value of storage modulus (G') and loss modulus (G″) of dough samples at all contents, G' and G″ value of dough sample containing 7% OPP was more than twice that of the wheat dough. Alveograph and rheofermentographic parameters confirmed that OPP improved the total volume of CO2 production from 1774.11 ml (wheat dough) to 2,458.30 ml (dough sample containing 7% OPP) but reduced the gas retention coefficient from 71.86% to 66.52% during fermentation accordingly. Additionally, no remarkable deterioration of the bread staling was observed. These results contributed to the interpretation of the action mechanism of OPP modification on the wheat dough structure and further guided the application of OPP on cereal product development.

Impact of defined thermomechanical treatment on the structure and content of dietary fiber and the stability and bioaccessibility of polyphenols of chokeberry (Aronia melanocarpa) pomace

Dietary fiber is a potential replacement for other ingredients such as starch in reformulated extruded breakfast cereals. Analysis of chokeberry pomace powder revealed a total dietary fiber content of 57.8 ± 2 g/100 g with 76% being insoluble, 20% high molecular soluble and 4% low molecular soluble dietary fiber. The fiber polysaccharide composition was analyzed in detail by using a variety of analytical approaches. Extrusion-like processing conditions were studies in a Closed Cavity Rheometer enabling the application of defined thermal (temperature range 100-160 °C) and mechanical treatments (shear rates between 0.1 s^-1 and 50 s^-1) to chokeberry pomace powder. Application of temperatures up to 140 °C irrespective of the mechanical treatment does not remarkably alter dietary fiber structure or content, but reduces the initial content of total polyphenols by about 40% to a final content of 3.3 ± 0.5 g/100 g including 0.63 ± 0.1 g/100 g of anthocyanins, 0.18 ± 0.02 g/100 g of phenolic acids and 0.090 ± 0.007 g/100 g of flavonols, respectively. The retained polyphenols are fully bioaccessible after in vitro digestion, and antioxidant capacity remains unchanged as compared to the untreated pomace powder. Glucose bioaccessibility remains unaffected, whereas glucose content is reduced. It is concluded that chokeberry pomace powder is a good source of dietary fiber with the potential to partially substitute starch in extruded breakfast cereals.

Management of Fruit Industrial By-Products-A Case Study on Circular Economy Approach

The management of industrial fruit by-products is important not only to decrease the volume of food waste accumulated in the landfills but also to develop strategies through reuse with the purpose to valorise and add economic value. The disposal of food waste leads to different global issues in different sectors, such as social, environmental and economical. These by-products represent a rich source of valuable compounds (polyphenols) with high antioxidant activity, which can be extracted through biotechnological methodologies for future industrial applications. In this context, the management of fruit by-products is challenged to move from a linear economy to a circular economy. Therefore, the purpose of this review is to provide a critical view of an integrated valorisation of fruit by-products to overcome a global issue, via the production of antioxidant extracts with high economic value. A case study of pineapple processing industrialization in a circular economy is explored and discussed.

Evaluation of the Fermentation Dynamics of Commercial Baker’s Yeast in Presence of Pistachio Powder to Produce Lysine-Enriched Breads

The present work was carried out to evaluate the microbiological, physicochemical, and sensory characteristics of fortified pistachio breads. Pistachio powder (5% w/w) was added to flour or semolina and fermented by a commercial baker’s yeast (Saccharomyces cerevisiae). Pistachio powder did not influence the biological leavening of the doughs. The kinetics of pH and total titratable acidity (TTA) during dough fermentation showed that the leavening process occurred similarly for all trials. The concentration of yeasts increased during fermentation and reached levels of 108 CFU/g after 2 h. Pistachio powder decreased the height and softness of the final breads and increased cell density of the central slices. The amount of lysine after baking increased in pistachio breads and this effect was stronger for semolina rather than flour trials. Sensory evaluation indicated that fortified breads processed from semolina were those more appreciated by the judges. This work clearly indicated that the addition of pistachio powder in bread production represents a promising strategy to increase the availability of lysine in cereal-based fermented products.

Improvement of gluten-free bread and cake properties using natural hydrocolloids: A review

The main wheat component responsible for bread and cake quality is gluten. Celiac disease is an autoimmune digestive disease that is caused by the digestion of gluten, and the only treatment of this disease is a gluten-free diet. Various gluten-free formulations (composite and wheatless flours) have applied gums (as gluten substitutes) to mimic the viscoelastic properties of gluten. In the bakery products, gums have been used to improve dough performance, bread and cake characteristics, textural and sensorial quality, and extension the products shelf life. This paper reviews the effect of the most common and new hydrocolloids (balangu seed, wild sage seed, basil seed, cress seed, xanthan, guar, starch carrageenan, methylcellulose, carboxy methyl cellulose, hydroxyl propyl methyl cellulose, and locust bean gums) on the rheological, physicochemical, textural, and quality characteristics of gluten-free breads and cakes. Gums affect gelatinization and retrogradation of starch through a strong association of amylose with gum, resulting in a decrease in the retrogradation of starch. Gums addition increased volume and porosity of the breads and cakes and resulted in softer products.

Exploring the Role of Cereal Dietary Fiber in Digestion

Increasing the dietary fiber of staple foods such as bread is an attractive way to promote healthy eating in a large part of the population, where dietary fiber consumption is reportedly below the recommended values. However, many consumers prefer white breads, which are typically low in dietary fiber. In this work, white bread was made from two wheat cultivars with differing fiber contents. The resulting breads showed similar quality parameters (volume, specific volume, firmness, inner structure characteristics) with any differences maintained below 7%. Bread digestibility was evaluated using a novel dynamic in vitro digestion model. Reduced digestion rates of 30% were estimated for the high-fiber white bread compared to that in the control. Overall, this work demonstrates the potential to produce healthy, high-fiber white breads that are acceptable to consumers, with a reduced rate of starch digestion, by exploiting a genetic variation in the dietary fiber content of wheat cultivars.

Dietary fibre from berry-processing waste and its impact on bread structure: a review

The structure and function of by-products of berry-processing industries are reviewed, with particular attention to dietary fibre (DF) and its effects in food products. The complex chemical composition and physicochemical characteristics of DF have been investigated and strategies for extraction of specific fractions that provide tailored technological and physiological functionality have been reviewed. The aim of this review is to describe in detail the structural composition and isolation methods of dietary fibre derived from berry by-products, and to explore their potential functionality in foods. The goal is to introduce DF from berry waste streams into the food chain, for which bread is a major vehicle. However, the appeal of bread lies in its aerated structure, for which DF is generally detrimental. The technological influence of DF on the formation and stabilization of the aerated structure of bread is therefore reviewed, in order to understand how to incorporate DF into bread while maintaining palatability. The aerated structure of bread is stabilized by two mechanisms: the gluten matrix and the liquid film surrounding bubbles. Incorporating DF successfully into bread requires understanding its interactions with both of these mechanisms. DF fractions from berries offer superior nutritional value compared to cereal fibre, potentially with less damage to bread structure, due to the higher proportion of soluble fibre. By-products from berry-processing industries could be used as a source of technologically and nutritionally distinctive DF to fabricate foods with enhanced nutritional value. © 2019 Society of Chemical Industry.