Vegetable By-products Research Articles

Dietary Fiber Concentrates from Fruit and Vegetable By-products: Processing, Modification, and Application as Functional Ingredients

The food industry is continuously looking for new sources of dietary fiber (DF) to use as an ingredient due to its well-known health benefits associated to its consumption. Usually, DF used for this purpose is obtained from cereal products or their by-products; however, by-products produced from the fruit and vegetable industry have comparatively higher DF content with more diverse compositions. DF concentrates (DFC), obtained by the processing of fruit and vegetable by-products, are suitable for food formulations because of their unique technological functionalities and applicabilities, both closely related to the DF composition. This review describes the DF definition and analytical procedures for its quantification, the processing of fruit and vegetable by-products aimed to obtain high quality DFC, as well as the control of the processing conditions to obtain DFC with specific functionalities. Furthermore, it deals with the role of the modifications by thermal and non-thermal technologies, as well as of the application of DFC in several food formulations.

Fruit and Vegetable By-Products to Fortify Spreadable Cheese.

In this work, spreadable cheese was enriched with flours from by-products (red and white grape pomace, tomato peel, broccoli, corn bran, and artichokes) as sources of fibres and antioxidant compounds. The physicochemical and the sensory properties of all the cheese samples were analysed. Results revealed that total phenolic content, flavonoids, and antioxidant activity of samples containing grape pomace significantly increased, followed by broccoli, artichoke, corn bran, and tomato peel by-products, compared to the control cheese. Specifically, cheeses containing white and red grape pomace recorded high phenolic content (2.74 ± 0.04 and 2.34 ± 0.15 mg GAEs/g dw, respectively) compared to the control (0.66 mg GAEs/g dw).

Functional Dehydrated Foods for Health Preservation

The market of functional foods has experienced a huge growth in the last decades due to the increased consumers’ awareness in a healthy lifestyle. Dried fruits constitute good snacks, in alternative to salty or sweet ones, and food ingredients due to their taste and nutritional/health benefits. Bioactive molecules are interesting sources to develop functional foods, as they play a major role in improving the health status and minimizing disease risks. The bioactive compounds most widely discussed in literature are presented in this review, for example, polyphenols, phytosterols, and prebiotics. Different technologies to dry bioproducts for producing functional foods or ingredients are presented. New drying techniques for the preservation of bioactive compounds are proposed, focusing more specifically on dielectric drying. A discussion on the techniques that can be used to optimize drying processes is performed. An overview on dehydrated plant based foods with probiotics is provided. The microorganisms used, impregnation procedures, drying methods, and evaluated parameters are presented and discussed. The principal bioactive compounds responsible for nutritional and health benefits of plant derived dried food products—fruits and vegetables, fruits and vegetables by-products, grains, nuts, and algae—are presented. Phytochemical losses occurring during pretreatments and/or drying processes are also discussed.

What a (Sometimes Inanimate) Divine Animal and Plant Has to Teach Us About Being Human: John’s Jesus and Other Nonhumans

The Jesus of John’s Gospel is not, or not solely, a human being. The god-man is also a nonhuman animal (a lamb), a vegetable (a vine), vegetable byproducts (bread and a door), and inorganic energy, namely, electromagnetic radiation (light)—all epithets no more or no less metaphoric than ‘Son of God’. Of course, it is Son christology that has commanded centre stage since at least the fourth century. The nonhuman turn in theory, elicited in no small part by the global ecological crisis, impels a shift of attention from Son christology to animal christology, vegetal christology, and inorganic christology. This article seeks to stage that shift, arguing that the Fourth Gospel enacts a profound disturbance of what Mel Chen has termed the animacy hierarchy: the world-structuring human ranking of inorganic material, plant life, animal life, disabled life, ‘fully human’ life—and, one might add, divine life—in terms of perceived intrinsic worth. The Johannine Jesus enacts animacy in multiple interpenetrating nonhuman ways that invite less anthropocentric modes of affective engagement than the Christs of classic orthodoxy, Christs supposedly modelled on the Johannine Jesus.

The Molecular Restructuring of Classical Desserts by Using Food Industry By-Products

Fruit and vegetable by-products are in general thrown away and can cause environmental problems, even though they are a valuable source of bioactive compounds, which may be used for innovative food production.The present work focused on achieving a new type of dessert, a “Sweetburger”, by restructuring its molecular components with the aid of molecular gastronomy techniques and using agro-industrial wastes (beetroot and sour cherry pulp and peels, melon pomace). The innovative dessert has been obtained and the bioactive compounds contained in the agro-industrial wastes have been characterized using the HPLC method, Folin-Ciocalteu and spectrophotometry. The total polyphenol content from sour cherries waste was significant, 508,9 mg gallic acid/100 g. The total anthocyanin content from beetroot pulp was 0,117 mg/ 100 g.

Optimisation and modelling of supercritical CO2 extraction process of carotenoids from carrot peels

This work aimed to assess and optimise the extraction of carotenoids from carrot peels by supercritical CO2 (S-CO2), utilising ethanol as co-solvent. The evaluated variables were temperature, pressure and co-solvent concentration. According to the validated model, the optimal conditions for maximum mass yield (5.31%, d.b.) were found at 58.5°C, 306bar and 14.3% of ethanol, and at 59.0°C, 349bar and 15.5% ethanol for carotenoid recovery (86.1%). Kinetic experiments showed that 97% of the total extractable carotenoid content was recovered after only 30min, whereas model fitting confirmed the fast extraction trend and desorbing nature of carotenoids from the sample matrix. The process is potentially scalable, as demonstrated by runs performed with a 10-fold initial sample size, which led to even higher recoveries (96.2%), indicating that S-CO2 can be as efficient as a conventional solvent extraction for recovering high value compounds from vegetable by-products.

Development and functional characterization of new antioxidant dietary fibers from pomegranate, olive and artichoke by-products

A novel ingredient acting as a slow digestible dietary fiber (DF) was developed by including native corn starch in calcium alginate microspheres (MS). In this study three types of antioxidant DF-rich ingredients were designed and developed by including in the MS, polyphenol-rich vegetable by-product extracts (obtained from pomegranate peels, olive leaves and artichoke leaves) and their potential functionality was assessed in vitro.Specifically, the physico-chemical properties of the new MS were compared with those of six commercially available DF concentrates and with wheat and oat brans. To evaluate the potential efficacy to release PPs along the gastrointestinal tract (GiT), pomegranate peels-microspheres (PPe-MS) were subjected to in vitro simulated gastrointestinal digestion. Results showed that the newly developed MS had higher free antioxidant capacity (free-TAC) than commercial DF rich products, and the bound antioxidant capacity (bound-TAC) of PPe-MS was comparable to that of wheat bran and 4.4 folds higher than that of oat-bran. Furthermore, it was shown that the release of ellagitannins from cooked PPe-MS along in vitro simulated gastro-intestinal digestion decreased from the salivary to the small intestine phase whereas gallic acid, ellagic acid and its derivatives had an opposite trend. A certain amount of PPs was found in the spent pellet obtained from the in vitro digestion, which was mimicking the residue reaching the colon in vivo. In conclusion data showed that the new antioxidant MS have physical-chemical properties like those of wheat and oat brans, mainly including the bound antioxidant capacity. This open to new possibilities of functional utilization of vegetable by-products for obtaining valuable and healthy food ingredients.

Incidence of the water-soluble compounds contained into lavender and sunflower bioaggregates on the hardening process of mineral binders

In building materials, the incorporation of plant aggregates into mineral matrix is an eco-friendly promising solution as these biobased building materials can answer to the new requirements for thermal and hydric performances. Nevertheless, plant aggregates can have deleterious effects on the hardening mechanisms of mineral binders. The aim of this study is to evaluate the incidence of the water-soluble compounds contained into bioaggregates on the hardening process of three mineral binders (CEMI 52.5 cement, metakaolin-based pozzolanic binder, limebased commercial binder). Two vegetal by-products were selected (lavender straw and sunflower depithed stalk) because of their large availability in France. Distilled lavender straw is the by-product of the steam distillation process applied to lavender plant. Sunflower bark aggregates were obtained from the fractionation of the entire stalk (i.e. bark plus pith). The chemical composition of the two bioaggregates was first studied by the ADF-NDF method of Van Soest and Wine. The cellulose, hemicellulose and lignin contents were thus determined. In addition, the water-soluble components were estimated by measuring the mass loss of the bioaggregates after 1 h in boiling water. Large differences were highlighted concerning the content in water-soluble compounds between the two plant aggregates. Model pastes were then elaborated with a solution obtained by soaking lavender or sunflower powder in demineralized water for 48 h and then filtering. The properties of the pastes were compared with those of neat pastes of the three mineral binders. The setting time (followed by isothermal calorimetry), the hardening mechanisms (followed by X-ray diffraction and thermogravimetric analysis) and the mechanical performance of the different binders were clearly and variously influenced by the lavender and the sunflower extractives at early ages. The level of the impact on the cementitious and pozzolanic binders can be correlated with the content in water-soluble compounds. Concerning the lime-based binder, it was less impacted by the water-soluble species.

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

ABSTRACTThe 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.

Effects of molasses on the fermentation characteristics of mixed silage prepared with rice straw, local vegetable by-products and alfalfa in Southeast China

This experiment was conducted to study the effect of molasses on the fermentation characteristics of mixed silage ensiled rice straw and vegetable by-products with alfalfa. Mixture (202 g kg−1 dry matter (DM)) consisting of rice straw, broccoli residue and alfalfa at the ratio of 5:4:1 was ensiled with three experimental treatments: (1) no additives (control); (2) molasses at 2.5% (M1); (3) molasses at 5% (M2) on a fresh matter basis of mixture, respectively. All treatments were packed into laboratory-scale silos, and three silos per treatment were sampled on days 1, 3, 5, 14 and 30. The result showed that the pH value of all mixed silages decreased gradually with the time of ensiling except for the control silage, in which a significant increase (P <0.05) on day 30 occurred. The lactic acid content increased gradually with the time of ensiling and reached the highest value on day 14, and a marked decrease (P <0.05) was found in the control silage on day 30. The changes of acetic acid content showed similar pattern with lactic acid content. A trace amount of propionic and butyric acid contents were found in the three mixed silages during the fermentation period. Comparing to the control, M1 and M2 treatments improved the fermentation quality of mixed silages as indicated by higher (P <0.05) lactic acid contents and lower (P <0.05) pH and ammonia-N contents. The Flieg points also showed that M1 and M2 silages were well preserved, whereas the control silage had a bad quality. Overall, the findings of this study suggested that adding molasses could improve fermentation quality of mixed silage, and M1 was more suitable for practical application.

Sandy Soil Modification by Bio-Composts for Wheat Production

Changes of the physicochemical characteristics of sandy soil, with low productivity, treated by the addition of eco and environmentally-friendly composts were evaluated. Two composts were produced from sludge of an urban wastewater treatment plant mixed with two different types of vegetable by-products, wood sawdust and straw. Studies were made on plant pots and two types of wheat were produced inside a greenhouse. Sandy soil tested was characterized before and after wheat production. The obtained results have shown increased levels of available nutrients as nitrogen, phosphorus, calcium and magnesium, an increase of the soil pH and an enhancement of the cationic exchange capacity of the soil as a function of the compost addition. On the other hand, the germination and growth of two types of wheat was improved by a factor of two and three, respectively in the amended soils. The beneficial effect of compost amendment was proportional to the employed dose. All results suggest that application of biocompost to sandy soil is a feasible option as a fertilizer substitute to supplement plant nutrient needs. This alternative material can replace environmentally dangerous and hazardous chemical products traditionally applied in agriculture.

Effect of hydrated apple powder on dough rheology and cookies quality

Dietary fiber is a group of food components, which are resistant to human enzymatic digestion. The incorporation of dietary fiber obtained from various sources of fruit and vegetable by-products into the cereal based products such as bread, rolls, cookies, muffins, crackers, cakes and pasta is of growing interest for the food industry. The replacement of wheat flour by dietary fiber from various sources can change physicochemical, textural and organoleptic characteristic of bakery products. Apple pomace is the main by-product produced in the apple fruit processing industry. It is a rich source of carbohydrate, pectin, crude fiber, and minerals. The dietary fiber content in apple pomace ranges between 33 - 35%. The influence of hydrated commercial dietary fiber on wheat dough rheology (5, 10 and 15% flour replacement) and physical and sensory properties of cookies was examined. It was found that addition of HAP significantly increased the rheological properties of dough such as water absorption (from 58.0% to 75.3%), dough stability (from 6.7 min to 11.6 min) and prolonged dough development time (from 3.5 min to 11.0 min) and reduced the mixing tolerance index (from 34.7 BU to 11.9 BU). It was also concluded that hydrated apple powder addition reduced physical properties of cookies such as volume (from 10.4 cm3 to 8.0 cm3), diameter (from 4.7 cm to 4.2 cm), volume index (from 1.35 cm to 1.10 cm) and porosity (from 0.32 to 0.24). Sensory properties (taste, odour, stickiness, firmness and density) of cookies were also analysed. Cookies with addition of hydrated apple powder had fruity taste and odour and showed high overall acceptance. From this study resulted that hydrated apple powder can be used as potentially source of dietary fiber in cookie formulation. Moreover, addition of apple pomace inhibits the use of any other flavouring ingredients because has a pleasant fruity flavour.

Ethyl lactate as a potential green solvent to extract hydrophilic (polar) and lipophilic (non-polar) phytonutrients simultaneously from fruit and vegetable by-products

Phytonutrients extracted from natural resources are receiving much attention among researchers due to their highly antioxidative characteristics which prevent several degenerative diseases including cardiovascular diseases and cancers. These nutraceutical compounds can be used in food, pharmaceutical and cosmetic products as natural antioxidants, preservatives, colourants and functional foods. Huge volume of food wastes are generated from the processing industry and these low-value food residues are rich in various phytonutrients worth recovering. This approach of valorisation reduces the generation of food wastes and is cost-effective considering the cheap feedstock, reduced waste management expenses and high market value of extracted compounds. In light of the health and safety risks posed by commonly used organic extraction solvents derived from the petrochemical industry, there is a need to recover the phytonutrients using green, sustainable and efficient solvents that are safe for human consumption. This work discusses ethyl lactate as a safe, green, efficient and potentially cheap solvent to recover phytonutrients from fruit and vegetable by-products. Ethyl lactate is compared with other organic solvents commonly used from the aspects of safety, environmental impacts and efficiency. Current challenges when employing ethyl lactate are also discussed.

Application of the pulsed electric field to release bound phenolics in sorghum flour and apple pomace

Abstract The mild intensity pulsed electric field (PEF) was studied to release bound phenolics in sorghum flour (SF) and apple pomace (AP). In this study, SF and AP, naturally fermented at optimized conditions, were treated at different flour to water ratios (FWRs) of 10, 27.5, 45% (w/v) and 5, 8.75, 12.5% (w/v), respectively. In addition, three levels of PEF electric field intensity (EFI) as 1, 2 and 3 kV/cm were used to treat SF and AP for the treatment time of 500, 875 and 1250 μs. Both the treated samples were analyzed for total phenolic content (TPC), antioxidant activity (AA) and phenolic characterization. For SF, optimized conditions were determined as 45% (w/v) FWR, 2 kV/cm EFI and 875 μs treatment time, while these values were 12.5% (w/v) FWR, 2 kV/cm EFI and 500 μs for AP. At these conditions, TPC and AA of SF were 24.8% and 33.9%, respectively higher than the control SF, while for AP, these numbers were observed as 37.4% and 86%, respectively. The study suggests that PEF treated SF and AP may be very useful for the preparation of processed foods with the increased levels of phenolic antioxidants. Industrial relevance Sorghum, millets and fruit or vegetable by-products contain high amounts of flavonoids and phenolic acids among other bioactive compounds. Results explicate that the application of a PEF treatment following the fermentation could improve the phenolic antioxidants in the sorghum flour and apple pomace. Consequently, this technology could be used in the food industry to enhance the healthy properties of millets and other by-products prior to further processing like mild extrusion or baking. Also the use of the mild intensity pulsed electric field has the benefit of minimizing any damage to the other nutrients of any product.

Towards a “dry” bio-refinery without solvents or added water using microwaves and ultrasound for total valorization of fruit and vegetable by-products

This study aims at total valorization of fruit and vegetable by-products, moving towards developing an original concept of “dry” bio-refinery (DBR).

Easy Method for Removal of Cyanogens from Cassava Leaves with Retention of Vitamins and Omega-3 Fatty Acids

Currently there is a crescent interest regarding the use of vegetable by-products for food fortification, in order to improve its nutritional quality. Cassava leaves are suitable as nutritional additives, however their cyanide content must be reduced to below 10 mg kg-1 of dry product. Thus, it was developed a method in drying laboratory oven which is able to reduce 99.85% of cyanide present in manioc leaves (from 35 mg kg-1 to 0.05 mg kg-1) while being 509% faster than the traditional method, and without substantial loss of omega-3 fatty acids and β-carotene.

Valorisation of food waste to produce new raw materials for animal feed

This study assesses the suitability of vegetable waste produced by food industry for use as a raw material for animal feed. It includes safety and nutritional viability, technical feasibility and environmental evaluation. Vegetable by-products were found to be nutritionally and sanitarily appropriate for use in animal feed. The drying technologies tested for making vegetable waste suitable for use in the animal feed market were pulse combustion drying, oven and microwave. The different meal prototypes obtained were found to comply with all the requirements of the animal feed market. An action plan that takes into account all the stages of the valorisation process was subsequently defined in agreement with local stakeholders. This plan was validated in a pilot-scale demonstration trial. Finally, the technical feasibility was studied and environmental improvement was performed. This project was funded by the European LIFE+ program (LIFE09 ENV/ES/000473).

Mussel processing wastewater: a low-cost substrate for the production of astaxanthin by Xanthophyllomyces dendrorhous.

BackgroundThe use of astaxanthin in different industries such as the chemical, pharmaceutical, food, animal feed and cosmetic has been receiving increasing attention in recent years. Natural supplies of the pigment include crustacean by-products, algal, and microbial cultivation, being the yeast Xanthophyllomyces dendrorhous together with the alga Haematococcus pluvialis the most promising microorganisms for this bioproduction. Different vegetable by-products of the food industry have been explored so far as low-cost substrates for the production of astaxanthin by X. dendrorhous. This study focuses for the first time on the use of a low-cost formulated medium from a marine by-product, mussel-processing wastewater, for the production of astaxanthin by the yeast X. dendrorhous.ResultsThe yeast was able to grow in non-saccharified mussel broth, revealing the ability of the microorganism to hydrolyze glycogen. However, partial glycogen saccharification with α-amylase was needed for astaxanthin biosynthesis, obtaining maximal productions of 22.5–26.0 mg/L towards the end of the culture and coinciding with yeast highest amylolytic activity. Cultivations in totally-saccharified media revealed an increase in maximal cell concentrations and a decrease in maximal growth rates and astaxanthin production with increasing glucose initial concentration.ConclusionsAstaxanthin production was higher in partially-saccharified mussel-processing waste than in synthetic medium (yeast peptone dextrose) containing glucose as carbon source (13 mg/L), suggesting this by-product is a promising nutritive medium for astaxanthin production. The use of this effluent also contributes towards the recycling and depuration of this highly pollutant effluent.

Advances in the Functional Characterization and Extraction Processes of Dietary Fiber

Dietary fiber has attracted interest due to its well-known physiological and functional properties. Several sources of this compound have been evaluated; however, the use of non-conventional matrices, such as fruits and vegetables by-products obtained from food processing industry, has recently gained attention. These fiber-rich by-products can be used as sources of functional ingredients to improve hydration properties, oil-holding capacity and rheological characteristics in different food products and with an important impact on health benefits. Thermal, chemical, enzymatic and mechanical/physical extraction methods have been used to obtain dietary fiber from different sources. However, in most cases the conditions used for these extractions imply long times and high temperatures that may modify the structure of the fiber obtained, changing also its functionality. Recent research has been focused on the use of emerging technologies (ultrasound, microwave and high-pressure processing) for assisted extractions in order to improve the fiber yield and also to maintain or enhance its functionality, reducing processing times and temperatures, and optimizing the usage of solvents. The critical insight into the advances in functionality and extraction processes of dietary fiber along with its definition, structural composition and sources is described in this review.

Concentrations of dioxins and dioxin-like PCBs in feed materials in the Netherlands, 2001–11

This study aimed to obtain insights into contamination of feed materials used in the Netherlands with dioxins (polychlorinated dibenzo-p-dioxins and dibenzofurans) and dioxin-like polychlorinated biphenyls (PCBs). Monitoring results from the period 2001–11, covering in total 4938 samples, were statistically analysed and evaluated against the statutory limits set at the beginning or during this period. The percentage of samples exceeding maximum levels set within the European Union for either dioxins or the sum of dioxins and dioxin-like PCBs were below 1% for most feed categories, except for fish meal (4.1%), clay minerals (binders and anti-caking agents) (3.4%), and vegetable oils and byproducts (1.7%). For most feed categories, non-compliance with the action threshold (roughly 33% lower than maximum levels) for either dioxins or dioxin-like PCBs was up to three times higher than non-compliance with the respective maximum levels. Exceedance of action thresholds was just above 1% for animal fat, pre-mixtures and feed materials of plant origin excluding vegetable oils. For the categories fish meal, clay minerals, and vegetable oils and byproducts, the action thresholds were exceeded by 5.0%, 9.8% and 3.0% of the samples, respectively. In general, the percentages of samples that exceeded the action thresholds and maximum levels were lower than those reported for the European Union by the European Food Safety Authority (EFSA). In most of the feed materials, there seems to be a decreasing trend in concentrations of dioxins or dioxin-like PCBs over the years. However, a lowering of the limits of quantification during this period and the low concentrations in most samples precludes drawing strong conclusions.