Fruit and vegetable by-products as novel ingredients to improve the nutritional quality of baked goods.

The industrial manufacturing of fruits and vegetables generates approximately 50% by-product waste, causing a negative environmental impact and significant expenses. Nevertheless, fruit and vegetable by-products (FVB) are rich nutrients and extranutritional compounds that contribute to bowel health, weight management, lower blood cholesterol levels and improved control of glycemic and insulin responses. Due to the positive influence of FVB fibers and bioactive compounds during the digestion of glycemic carbohydrates, such as starch, baked goods are ideal food systems to accommodate FVB, since most of them have a high glycemic index. Therefore, this is an area of recent interest with critical environmental, economic and health implications worldwide. However, the utilization of FVB in baked goods leads to the loss of acceptability, in many cases caused by a lack of understanding of the physical structure and composition of FVB and their effects on food quality. The objective of this review is to provide a mechanistic understanding of the impact of the physical structure and composition of FVB on common baked goods and their influence on the nutritional and physical quality of the resulting product. This review will support the use of FVB as ideal ingredients while improving the added value of waste streams.

Ripe Banana Flour as a Source of Antioxidants in Layer and Sponge Cakes.

About one-fifth of all bananas harvested become culls that are normally disposed of improperly. However, ripe banana pulp contains significant amounts of fibre and polyphenol compounds as well as a high content of simple sugars (61.06 g/100 g), making it suitable for sucrose replacement in bakery products. This work studied the feasibility of incorporating ripe banana flour (20 and 40% of replacement) in cake formulation. Physical, nutritional and sensory attributes of sponge and layer cakes were evaluated. The inclusion of ripe banana flour generally led to an increased batter consistency that hindered cake expansion, resulting in a slightly lower specific volume and higher hardness. This effect was minimised in layer cakes where differences in volume were only evident with the higher level of replacement. The lower volume and higher hardness contributed to the decline of the acceptability observed in the sensory test. Unlike physical attributes, the banana flour inclusion significantly improved the nutritional properties of the cakes, bringing about an enhancement in dietary fibre, polyphenols and antioxidant capacity (up to a three-fold improvement in antioxidant capacity performance). Therefore, results showed that sugar replacement by ripe banana flour enhanced the nutritional properties of cakes, but attention should be paid to its inclusion level.

Effect of extruded wheat flour as a fat replacer on batter characteristics and cake quality.

The effects of three levels of fat replacement (1/3, 2/3, and 3/3) by extruded flour paste and the effects of the presence of emulsifier on layer cake batter characteristics and final cake quality were studied. Replacement of oil by extruded flour paste modified the batter density and microscopy, reducing the number of air bubbles and increasing their size, while emulsifier incorporation facilitated air entrapment in batter. Emulsifier addition also increased the elastic and viscous moduli of the batter, while oil reduction resulted in a less structured batter. Emulsifier incorporation leads to good quality cakes, minimizing the negative effect of oil reduction, maintaining the volume and reducing the hardness of cakes. Furthermore, consumer acceptability of the reduced fat cakes was improved by the addition of emulsifier. Thus, the results confirmed the positive effect of partial oil substitution (up to 2/3) by extruded flour paste on the quality of reduced fat cakes when emulsifier was incorporated.

Mixture design of rice flour, maize starch and wheat starch for optimization of gluten free bread quality.

Gluten-free bread production requires gluten-free flours or starches. Rice flour and maize starch are two of the most commonly used raw materials. Over recent years, gluten-free wheat starch is available on the market. The aim of this research was to optimize mixtures of rice flour, maize starch and wheat starch using an experimental mixture design. For this purpose, dough rheology and its fermentation behaviour were studied. Quality bread parameters such as specific volume, texture, cell structure, colour and acceptability were also analysed. Generally, starch incorporation reduced G* and increased the bread specific volume and cell density, but the breads obtained were paler than the rice flour breads. Comparing the starches, wheat starch breads had better overall acceptability and had a greater volume than maize-starch bread. The highest value for sensorial acceptability corresponded to the bread produced with a mixture of rice flour (59 g/100 g) and wheat starch (41 g/100 g).

Exploring novel organocatalytic-acetylated pea starch blends in the development of hot-pressed bioplastics.

Acetylated starch shows enhanced thermal stability and moisture resistance, but its compatibilization with other more hydrophilic polysaccharides remains poor or unknown. In this study, the feasibility of thermomechanically compounding organocatalytically acetylated pea starch (APS), produced at two different degrees of substitution with alkanoyl groups (DSacyl, 0.39 and 1.00), with native pea starch (NPS), high (HMP) and low methoxyl (LMP) citrus pectin, and sugar beet pectin (SBP, a naturally acetylated pectin) for developing hot-pressed bioplastics was studied. Generally, APS decreased hydrogen bonding (ATR-FTIR) and crystallinity (XRD) of NPS films at different levels, depending on its DSacyl. The poor compatibility between APS and NPS or HMP was confirmed by ATR-FTIR imaging. Contrariwise, APS with DSacyl 1 was effectively thermomechanically mixed with the acetylated SBP matrix, maintaining homogeneous distribution within it (ATR-FTIR imaging). APS (any DSacyl) significantly increased the visible/UV light opacity of NPS-based films and decreased their water vapor transmission rate (WVTR, by ca. 11 %) and surface water wettability (by ca. 3 times). In comparison to NPS-APS films, pectin-APS showed higher visible/UV light absorption, tensile strength (ca.2.9-4.4 vs ca.2.4 MPa), and Young's modulus (ca.96-116 vs ca.60-70 MPa), with SBP-APS presenting significantly lower water wettability than the rest of the films.

Unraveling the neutral and polar lipidome of Nordic brown macroalgae: A sustainable source of functional lipids.

Brown macroalgae represent a sustainable and abundant source of lipids with acknowledged functional and health benefits. Nonetheless, macroalgae lipidome has been poorly unraveled due to lipids complex structural and chemical diversity. In this study, a comprehensive lipidomic analysis was performed in four macroalgae: Saccharina latissima, Fucus vesiculosus, Fucus serratus and the invasive Sargassum muticum, using HILIC-C30RP-HRMS. Neutral lipids (tri-, di-glycerides) comprised 72-82% of total lipids (TL) with a highly unsaturation profile (27-49% depending on species). The polar lipidome comprised glycolipids, phospholipids, betaine lipids and sphingolipids with varied content among macroalgae. S. latissima displayed the greatest level of glycolipids (23% of TL), by contrast with the dominance of long-chain polyunsaturated betaine lipids (10-18% of TL) in the other species, particularly in S. muticum. Phospholipids and sphingolipids were detected in low abundance (<1.7% of TL). This study elevated the potential of brown macroalgae as an emerging reservoir of bioactive lipids with nutritional relevance.

Molecular changes and interactions of wheat flour biopolymers during bread-making: Implications to upcycle bread waste into bioplastics.

This study aims to understand the molecular and supramolecular transformations of wheat endosperm biopolymers during bread-making, and their implications to fabricate self-standing films from stale white bread. A reduction in the Mw of amylopectin (51.8 × 106 vs 425.1 × 106 g/mol) and water extractable arabinoxylans WEAX (1.79 × 105 vs 7.63 × 105 g/mol), and a decrease in amylose length (245 vs 748 glucose units) was observed after bread-baking. The chain length distribution of amylopectin and the arabinose-to-xylose (A/X) ratio of WEAX remained unaffected during bread-making, suggesting that heat- or/and shear-induced chain scission is the mechanism responsible for molecular fragmentation. Bread-making also resulted in more insoluble cell wall residue, featured by water unextractable arabinoxylan of lower A/X and Mw, along with the formation of a gluten network. Flexible and transparent films with good light-blocking performance (<30 % transmittance) and DPPH-radical scavenging capacity (~8.5 %) were successfully developed from bread and flour. Bread films exhibited lower hygroscopicity, tensile strength (2.7 vs 8.5 MPa) and elastic modulus (67 vs 501 MPa) than flour films, while having a 6-fold higher elongation at break (10.0 vs 61.2 %). This study provides insights into the changes in wheat biopolymers during bread-making and sets a precedent for using stale bread as composite polymeric materials.

Partitioning and in vitro bioaccessibility of apple polyphenols during mechanical and physiological extraction: A hierarchical clustering analysis with LC-ESI-QTOF-MS/MS.

Polyphenol partitioning during mechanical (cold-pressing) and physiological (digestion) extraction at the individual polyphenol and subclass level was investigated. UHPLC-ESI-QTOF-MS/MS analysis yielded a comprehensive identification of 45 polyphenols whose semi-quantification revealed a hierarchical clustering strongly determined by polyphenol structure and their location within the apple tissue. For instance, pomace retained most flavonols and flavanols (degree of polymerization DP 5-7), which were highly hydrophobic, hydroxylated, or large (>434 Da), and more abundant in peel. In vitro digestion UHPLC-ESI-QTOF-MS/MS analysis of whole apple (and its corresponding matrix-free extract) clustered polyphenols into five main groups according to their interaction with plant cell walls (PCWs) during each digestion phase. This grouping was not reproduced in pomace, which exhibited a greater matrix effect than whole apple during oral and gastric digestion. Nevertheless, the interaction between most polyphenol groups, including dihydrochalcones, flavanols (DP 1-4) and hydroxycinnamic acid derivatives, and pomace PCWs was lost during intestinal digestion.

Preparation and characterization of self-standing biofilms from compatible pectin/starch blends: Effect of pectin structure.

Pectin structure-miscibility-functionality relationships in starch films remain unknown. In this study, five citrus pectins (CPs) with 17 to 63 % of degree of methyl esterification (DM) and sugar beet pectin (SBP, rich in acetyl moieties and rhamnogalacturonan-I domains) were investigated for composition and structure and, further, blended with pea starch (3:1 starch-pectin weight ratio) to fabricate self-standing films. The incorporation of pectin resulted in a two- to three-fold increase in tensile strength and Young's modulus (up to 52.2 and 1837 MPa, respectively, using CP with low DM) without compromising elongation at break. Starch-SBP films presented the lowest strength among pectin films. Lower film moisture and water vapor permeability were attained with CP of high DM, or with SBP, whereas surface wettability was explained by counteracting factors affecting film compositional heterogeneity. Films made with high methoxyl CP, or with SBP, showed lower overall H-bonding (FTIR) and starch crystallinity (XRD). A DM above 57 % negatively affected the mixing and interfacial adhesion of pectin with starch, as shown by Attenuated Total Reflection-FTIR imaging. Pectins with the lowest purity, presumably with the greatest content in xyloglucan, as suggested by HPAEC, presented ~20 % higher elongation at break than the other films.

Untargeted screening and in silico toxicity assessment of semi- and non-volatile compounds migrating from polysaccharide-based food contact materials.

The chemical safety of representative polysaccharide films made with pea starch, organocatalytic acetylated pea starch and pectin was investigated at different migration conditions (20 °C/10 days, 70 °C/2 h) using two official simulants signifying hydrophilic (simulant A, 10% ethanol) or lipophilic (simulant D1, 50% ethanol) foods. Migrating semi-volatile and non-volatile compounds were identified and semi-quantified by ultra-high performance liquid chromatography-trap ion mobility time-of-flight mass spectrometry (UHPLC-TIMS-TOF-MS/MS), whereas their toxicity was evaluated by in silico models based on qualitative structure activity (QSAR). Physicochemical analysis revealed polymer wash-off into the simulants. Migration testing at 70 °C for 2 h using simulant D1 resulted in detectable concentrations of glycerol (≤72.1 mg/kg), monoacetylated maltose (≤6.5 mg/kg), and dibutyl phthalate (DBP) (≤0.5 mg/kg, compliant with the existing legislative migration limits) in samples containing acetylated starch. Migrating 3-ß-galactopyranosyl glucose (≤8.9 mg/kg) and 2,5-diketo-d-gluconic acid (≤4.9 mg/kg) were detected at 20 °C/10 days. In-silico toxicity emphasized no significant toxicity and categorized organocatalytic acetylated pea starch of no safety concern.

Fucose modifies short chain fatty acid and H2S formation through alterations of microbial cross-feeding activities.

Algae are a rich but unexplored source of fibers with the potential to contribute to the next generation of prebiotics. The sulfated brown algae polysaccharide, fucoidan, is mainly composed of the deoxy-hexose L-fucose, which can be metabolized to 1,2-propanediol (1,2-PD) or lactate by gut microbes as precursors of propionate and butyrate. It was the aim of this study to investigate the impact of fucoidan on the fermentation capacity of the fecal microbiota and to compare to fucose. In batch fermentations of fecal microbiota collected from 17 donor samples, fucose promoted the production of propionate while no consistent effect was observed for commercial fucoidan and Fucus vesiculosus extract prepared in this study containing laminarin and fucoidan. H2S production was detected under all tested conditions, and levels were significantly lower in the presence of fucose in a dose-dependent manner. The addition of high fucose levels led to higher relative abundance of microbial 1,2-PD and lactate cross-feeders. Our results highlight that fucose and not fucoidan addition impacted fermentation capacity and increased the proportions of propionate and butyrate, which allows for precise modulation of intestinal microbiota activity.

Organocatalytic acetylation of pea starch: Effect of alkanoyl and tartaryl groups on starch acetate performance.

Organocatalytic acetylation of pea starch was systematically optimized using tartaric acid as catalyst. The effect of the degree of substitution with alkanoyl (DSacyl) and tartaryl groups (DStar) on thermal and moisture resistivity, and film-forming properties was investigated. Pea starch with DSacyl from 0.03 to 2.8 was successfully developed at more efficient reaction rates than acetylated maize starch. Nevertheless, longer reaction time resulted in granule surface roughness, loss of birefringence, hydrolytic degradation, and a DStar up to 0.5. Solid-state 13C NMR and SEC-MALS-RI suggested that tartaryl groups formed crosslinked di-starch tartrate. Acetylation increased the hydrophobicity, degradation temperature (by ~17 %), and glass transition temperature (by up to ~38 %) of pea starch. The use of organocatalytically-acetylated pea starch with DSacyl ≤ 0.39 generated starch-based biofilms with higher tensile and water barrier properties. Nevertheless, at higher DS, the incompatibility between highly acetylated and native pea starches resulted in a heterogenous/microporous structure that worsened film properties.

Pregelatinized Drum-Dried Wheat Starch of Different Swelling Behavior as Clean Label Oil Replacer in Oil-in-Water Emulsions.

Drum-drying results in pregelatinized starch with relatively low starch fragmentation and a great ability to absorb water and swell at room temperature. However, the effect of the degree of cold particle swelling and the thickening potential of drum-dried starch on its suitability as oil replacer in low-fat oil-in-water emulsions has received little attention. In this work, the potential of three pregelatinized drum-dried starches with almost identical molecular structure (as measured by size exclusion chromatography) and Water Binding Capacity (WBC), but different swelling behavior, was investigated to replace up to 60% oil in a mayonnaise-like emulsion system. The microstructure, stability, and rheology of the oil-in-water emulsions were noticeably affected by the substitution of oil with a pregelatinized drum-dried starch paste. Specifically, reduced-fat emulsions presented smaller droplet-size, a higher consistency index and increased emulsion stability, especially against freeze-thaw cycles, compared to the control full-fat mayonnaise. Importantly, the differences in cold swelling behavior (rather than simply assessing WBC) greatly influenced the consistency index and stability of low-fat emulsions, and results showed that drum-dried starch particles with high swelling potential perform better as oil replacers.

Changes to fine structure, size and mechanical modulus of phytoglycogen nanoparticles subjected to high-shear extrusion.

This study aims to enhance the understanding of the structure of maize phytoglycogen nanoparticles, and the effect of shear scission on their architecture, radius, stiffness, and deformability. Compared to amylopectin, phytoglycogen had a lower A:B chain ratio, a lower number of chains per B chain, and a much higher number of Afingerprint chains. Phytoglycogen (Mw = 28.0 × 106 g/mol) was subjected to high-shear extrusion with varying Specific Mechanical Energies (SMEs) using different screw speeds, showing a maximum stable molecular weight Mw of ∼9.31 × 106 g/mol and a particle radius R reduction of 36 %, with a corresponding 20 % increase in the average mass density. Atomic force microscopy force spectroscopy revealed that nanoparticles extruded at the lowest SME (122 Wh/kg) exhibited a 20 % increase in Young's modulus. Higher SME values (up to 488 Wh/kg) resulted in an overall decrease in stiffness without further significant reductions in radius.

The effect of extruded breadfruit flour on structural and physicochemical properties of beef emulsion modeling systems.

The objective was to determine structural and physicochemical properties of beef emulsion modeling systems prepared with native breadfruit flour and four different extruded breadfruit flours. Extrusion conditions for the flours were summarized as two different specific mechanical energies (74 or 145 kJ/kg) and four unique melt temperatures (83 °C, 100 °C, 105 °C, or 126 °C). Meat emulsions formulated at 3% replacement of beef with native or extruded breadfruit flours were compared with control (no additional flour) formulations. Replacement of beef with breadfruit flour (either native or extruded) did not significantly change cooking loss or instrumental redness values of cooked meat emulsions. Interestingly, replacement of beef with the fully gelatinized extruded breadfruit flours altered viscosity during heating as indicated by lower values for storage modulus (44.75% to 62.53% decrease compared with control) and lower values for loss modulus (25.90% to 52.54% decrease compared with control). This resulted in meat emulsions with a significant reduction in textural hardness (28.78% to 37.62% decrease compared with control).

Co-extruded wheat/okra composite blends result in soft, cohesive and resilient crumbs rich in health-promoting compounds.

This work investigates the partial solubilization of cell wall polysaccharides in okra flours and the changes in the profile of free and bound phenolics through twin-screw extrusion. The comparison between extruded wheat flour-native okra flour (EWF-OF) and extruded wheat flour-extruded okra flour (EWF-EOF) composite blends revealed that extrusion led to an increase of soluble dietary fiber from 7.76 to 10.02 g/100 g. Extrusion of okra also resulted in a significant increase of free and bound phenolic acids, the latter consisting mostly of ferulic acid, as well as the thermal degradation of free epigallocatechin, and the binding of a small portion of quercetin-3-O-glucoside likely to a carbohydrate fraction. Bread crumbs from EWF-EOF (at 15% replacement level) exhibited a significantly lower hardness and higher elasticity, cohesiveness and resilience (from 28.28 N, 0.94, 0.49 and 0.17 to 7.54 N, 0.99, 0.70 and 0.35, respectively), which closely resembled the textural attributes of wheat bread.

Development and assessment of GC/MS and HPAEC/PAD methodologies for the quantification of α-galacto-oligosaccharides (GOS) in dry beans (Phaseolus vulgaris).

The quantification of α-Galacto-oligosaccharides (GOS) in beans has been increasingly approached through different methodologies. However, reported GOS contents revealed up to 8-times disparity, which cannot be only attributed to the bean cultivar and underlines the need of using validated analytical methodologies. This study aimed to optimize and validate the extraction of the most abundant GOS found in beans, namely raffinose, stachyose and verbascose, and comparatively assess their determination by High-Performance Anion Exchange Chromatography/Pulsed Amperometric Detector (HPAEC/PAD) and Gas Chromatography/Mass Spectrometry (GC/MS). Hot sonication followed by shaking with 70% ethanol resulted in excellent GOS extraction efficiencies (92.54-107.94%). GC/MS determination was more reliable than HPAEC/PAD, with limits of quantification of 4.48-224.31 mg/kg and intra/inter-day repeatabilities <10%. The analysis of six bean varieties proved the feasibility of the GC/MS methodology, displaying total GOS contents from 1453.07 ±â€¯169.31 to 2814.34 ±â€¯95.28 mg/100 g. Stachyose was significantly (p < 0.05) the main GOS in all samples.

Systematic evaluation of the Folin-Ciocalteu and Fast Blue BB reactions during the analysis of total phenolics in legumes, nuts and plant seeds.

Folin-Ciocalteu and the more recent Fast Blue BB (FBBB) reactions are used for the quantification of total phenolics in food matrices. Despite its known interferences, Folin-Ciocalteu is still widely employed, considering Solid Phase Extraction (SPE) as clean-up step only in a few cases. Meanwhile, FBBB has shown no interferences for the determination of total phenolics in fruits and cereals, although its utilization in other popular matrices containing potential interferences, such as legumes, remains unexplored. In this study, the total phenolic content of 24 flours from legumes, cereals, fruits, nuts and plant seeds was evaluated by Folin-Ciocalteu and FBBB, with and without SPE. Folin-Ciocalteu showed interferences for 75% of the flours (attributed to reducing sugars and enediols), whereas FBBB only for legumes and nuts (attributed to the presence of tyrosine), both methods in those matrices requiring SPE. Although both SPE-FBBB and SPE-Folin-Ciocalteu presented excellent reproducibility, SPE-FBBB displayed 1.5 times higher sensitivity.

Modification of Physicochemical Properties of Breadfruit Flour Using Different Twin-Screw Extrusion Conditions and Its Application in Soy Protein Gels.

The objective was to modify functional properties of breadfruit flours using twin-screw extrusion and test the physicochemical properties of the extruded flours. Extruded breadfruit flours were produced with twin-screw extrusion using different last barrel temperature (80 °C or 120 °C) and feed moisture content (17% or 30%). These conditions resulted in four extruded flours with different mechanical (specific mechanical energy, SME) and thermal (melt temperature) energies. At temperatures below the gelatinization of the native starch (<70 °C), swelling power was increased in all extruded treatments. Solubility was dramatically increased in high-SME extruded flours at all tested temperatures. Water holding capacity was dramatically increased in the low-SME extruded flours. A two-fold higher cold peak viscosity was obtained for low SME-high temperature extruded flour compared with the other extruded flours. Low SME-low temperature extruded flour still exhibited a hot peak viscosity, which occurred earlier than in native flour. Setback was decreased in all extruded flours, especially in high-SME treatments. The incorporation of extruded flours into soy protein gels did not affect cooking loss, while hardness and springiness decreased with the addition of extruded flours. Overall, extrusion of breadfruit flour altered functional flour properties, including water holding capacity and pasting properties, and modified the texture of soy protein gels.

Fine structure, physicochemical and antioxidant properties of LM-pectins from okra pods dried under different techniques.

This work investigates the effect of drying okra pods by different techniques [freeze-drying (FD), sun-drying (SD), oven-drying (OD) and microwave-drying (MD)] on the molecular structure, physicochemical and antioxidant properties of the subsequently extracted OP. Remarkably, although the degree of methyl esterification (∼41.1 %) remained similar among samples, the content of galacturonic acid (62.67-68.77 %), average number molecular weight (MnI: 758.8-808.5 kDa, MnII: 20.9-24.2 kDa), and to a greater extent the apparent viscosity of an aqueous solution of pectin molecules, water holding capacity (0.21-10.71 g/g) and emulsifying activity (42.3-72.7 %) and stability (38.6-53.5 %), decreased with the drying temperature in the order of FD-OP > SD-OP > OD-OP > MD-OP. On the other hand, only FD-OP presented a higher proportion of galactan and/or arabinan side chains [(Ara + Gal) / Rha = 12.37%] compared to the rest of the samples, with values ranging from 7.79 to 9.17%. FD-OP and SD-OP resulted in lower DPPH and ABTS radical scavenging activities.