Techno-functional properties of dry-fractionated plant-based proteins and application in food product development: a review.

Dry-fractionated protein concentrates are gaining attention because they are produced using a versatile and sustainable technology, which can be applied to a wide range of plant material. To facilitate their utilization in new product development, it is crucial to obtain a comprehensive overview of their techno-functional properties. The present review aims to examine the techno-functional properties of dry-fractionated protein concentrates and describe their primary applications in food products, considering the published works in the last decade. The techno-functional properties of proteins, including water absorption capacity, emulsifying and foaming properties, gelling ability or protein solubility, are relevant factors to consider during food formulation. However, these properties are significantly influenced by the extraction technology, the type of protein and its characteristics. Overall, dry-fractionated proteins are characterized by high protein solubility, high foaming ability and foam stability, and high gelling ability. Such properties have been exploited in the development of food, such as bakery products and pasta, with the aim of increasing the protein content and enhancing the nutritional value. Additionally, innovative foods with distinctive textural and nutritional characteristics, such as meat and dairy analogues, have been developed by using dry-fractionated proteins. The results indicate that the study of these ingredients still needs to be improved, including their application with a broader range of plant materials. Nevertheless, this review could represent an initial step to obtaining an overview of the techno-functional properties of dry-fractionated proteins, facilitating their use in foods. © 2023 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Dry-fractionated protein concentrate as egg replacer in sponge cake: how the rheological properties of the batters affect the physical and structural quality of the products.

BACKGROUND: Egg replacement is a notable food trend for academics and industry. Dry-fractionated protein concentrates (DFp) are minimally processed and sustainable ingredients. DFp from chickpea, red lentil and mung bean, prepared as aqueous dispersions at 20-40% (w/w), were used to replace egg in sponge cakes. To understand the effect of DFp on the physicochemical features of sponge cakes, the batter rheological properties (i.e., flow behavior, frequency-dependent and temperature-dependent behaviors) were investigated. RESULTS: Frequency sweep revealed a higher storage modulus (G') than loss modulus (G″), indicating predominantly elastic-like behavior, dependent on the frequency. Increasing DFp content, especially at 40%, resulted in firmer batters, indicated by elevated apparent viscosity. During temperature sweep, G' increased starting from 80 °C in all DFp-based batters, indicating protein and starch conformational changes. Higher DFp content better simulated the egg behavior, affecting specific volume and thickness variation after baking but resulting in harder cakes. Crumb structure was similar to the control, highlighting that DFp can emulate the egg behavior in cake preparation. Protein content in cakes containing 30% DFp was similar to the control. However, the addition of DFp caused an increase in phytic acid. Sensory analysis of sponge cakes revealed differences in crust color, sweetness and legume flavor, with minimal effect on astringency. Chickpea and lentil DFp are suggested as preferred alternatives because of their to milder sensory impact. CONCLUSION: Overall, eggs in cake formulation can be substituted by plant-based protein produced by dry fractionation. However, further research is essential to evaluate the nutritional characteristics. © 2023 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Feasibility of excitation-emission fluorescence spectroscopy in tandem with chemometrics for quantitation of trans-resveratrol in vine-shoot ethanolic extracts.

BACKGROUND: trans-Resveratrol (TR) is a well-known phytochemical compound with important biological properties. It can be recovered from agri-food by-products or wastes, such as vine shoots. Once recovered, its concentration should be measured, possibly in a green, non-destructive, and efficient manner. With these premises, this work aimed to explore the feasibility of excitation-emission fluorescence spectroscopy combined with chemometrics for the analysis of TR in raw extracts obtained from vine shoots. A total of 75 extracts were produced and analyzed by ultra-performance liquid chromatography method with diode array detection (UPLC-DAD) and spectrofluorimetry. Then, the feasibility of two calibration strategies for TR quantitation was assessed - a parallel factor analysis (PARAFAC)-based calibration and the N-way partial least squares (NPLS) regression. RESULTS: The extracts showed variable TR content, the excitation/emission maxima of which were at around 305/390 nm, respectively. The best PARAFAC-based calibration allowed a root mean square error of prediction (RMSEP) of 22.57 mg L-1 , and a relative prediction deviation (RPD) of 2.91 to be obtained but a large number of PARAFAC components should be considered to improve the predictions. The results of the NPLS regression were slightly better, with a RMSEP of 19.47 mg L-1 , and an RPD of 3.33 in the best case. CONCLUSION: Fluorescence could be an alternative analytical technique to measure TR in complex samples. Chemometric tools allowed the identification of the TR signal in the fluorescence landscapes, which could be further used for its non-destructive quantitation. The need for a more accurate criterion for optimal PARAFAC complexity emerged. © 2024 Society of Chemical Industry.

Acute Consumption of Cooked Green Banana Pulp Beverage (Musa cavendishii) Decreases Plasma Glucose in Healthy Women: A Cross-Sectional Controlled Study.

This study aimed at comparing the carbohydrate composition of three banana varieties (cv. Nanica, Nanicão, and Prata) and investigating the effect of a single dose of cooked green banana pulp beverage (GBPd) on plasma glycemic homeostasis indexes (glucose, PYY, GIP, insulin) and hunger and satiety sensation (visual analog scale-VAS). The bananas were classified according to the color scale. The fiber, total carbohydrate, and resistant starch (RS) were determined using validated methods. Glucose homeostasis indexes and hunger/satiety sensation were determined in ten healthy women in two stages before and after intake: (1) glucose solution (250 g/L); (2) one week later, consumption of the glucose solution plus 75 g/L of GBPd. Blood samples were collected twice in stage-1 and every 15 min for 2 h in stage-2. Cv. Nanicão was selected, because it presented a higher content in RS and dietary fiber on dry base than the other cultivars. Thus, it was used to test glycemic response. After 2 h of GBPd intake, no difference was observed in hunger/satiety sensation and plasma glycemic homeostasis indexes, except for a decrease in plasma glucose concentration (-15%, p = 0.0232) compared to stage-1. These results suggest that cv. Nanicão has a higher potential as a functional ingredient and can influence the reduction in the glycemic index of a meal compared to other cultivars. However, it had not a short-term effect on hormones GIP and PYY in healthy women. Further research is needed to understand the long-term effects and mechanisms of green banana on glycemic control and satiety.

Almond okara as a valuable ingredient in biscuit preparation.

BACKGROUND: The okara is the water-insoluble residue derived from the production of plant-based beverages, including almond milk. Information on almond okara is scarce, with no scientific references. In the present study, the almond okara was characterized and used to replace wheat flour at 15%, 25% and 35% for biscuit preparation. RESULTS: The contents of protein, lipid and dietary fiber of almond okara were 140.08, 421.16 and 407.90 g kg-1 dry matter, respectively. The lipid fraction of almond okara showed contents of triacylglycerol oligopolymers and oxidized triacylglycerols of 0.12 and 5.14 g kg-1 , respectively, which were significantly lower than the levels observed in the sunflower oil used in the formulation of biscuits. Consequently, the biscuits containing okara showed a content of triacylglycerol oligopolymers lower than that of control biscuits. The texture analysis revealed that the addition of the okara at 25% and 35% caused a significant increase in biscuit hardness and a reduction of the brittleness, compared to the control. The sensory evaluation confirmed these data, highlighting the slight impact of the almond okara on the almond odor, taste and flavor attributes. CONCLUSION: Almond okara is a valuable by-product that can be easily used as an ingredient for biscuit preparation, exploiting its fiber, protein and lipid content to improve the nutritional value of food, with a limited impact on the sensory properties. © 2022 Society of Chemical Industry.

Legumes as basic ingredients in the production of dairy-free cheese alternatives: a review.

Research into dairy-free alternative products, whether plant-based or cell-based, is growing fast and the food industry is facing a new challenge of creating innovative, nutritious, accessible, and natural dairy-free cheese alternatives. The market demand for these products is continuing to increase owing to more people choosing to reduce or eliminate meat and dairy products from their diet for health, environmental sustainability, and/or ethical reasons. This review investigates the current status of dairy product alternatives. Legume proteins have good technological properties and are cheap, which gives them a strong commercial potential to be used in plant-based cheese-like products. However, few legume proteins have been explored in the formulation, development, and manufacture of a fully dairy-free cheese because of their undesirable properties: heat stable anti-nutritional factors and a beany flavor. These can be alleviated by novel or traditional and economical techniques. The improvement and diversification of the formulation of legume-based cheese alternatives is strongly suggested as a low-cost step towards more sustainable food chains. © 2021 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Potential use of plant-based by-products and waste to improve the quality of gluten-free foods.

The food industry generates a large amount of waste and by-products, the disposal of which has a negative impact on the environment and the economy. Plant-based waste and by-products are rich in bioactive compounds such as dietary fiber, proteins, essential fatty acids, antioxidant compounds, vitamin, and minerals, which can be exploited to reduce the nutritional deficiencies of gluten-free products. The latter are known to be rich in fats and carbohydrates but lacking in bioactive compounds; the absence of gluten also has a negative effect on textural and sensory properties. Several attempts have been made to improve the quality of gluten-free products using alternative flours and additives, or by adopting innovative technologies. The exploitation of plant-based by-products would represent a chance to improve both the nutritional profile and the overall quality of gluten-free foods by further enhancing the sustainability of the agri-food system. After examining in detail the composition of plant-based by-products and waste, the objective of this review was to provide an overview of the effects of their inclusion on the quality of gluten-free products (bread, pasta, cake/muffins, biscuits and snacks). The advantages and drawbacks regarding the physical, sensory, and nutritional properties were critically evaluated. © 2021 Society of Chemical Industry.

Spreadable plant-based cheese analogue with dry-fractioned pea protein and inulin-olive oil emulsion-filled gel.

BACKGROUND: Consumer demand for plant-based cheese analogues (PCA) is growing because of the easy and versatile ways in which they can be used. However, the products available on the market are nutritionally poor. They are low in protein, high in saturated fat and sodium, and often characterized by a long list of ingredients. RESULTS: A clean label spreadable plant-based cheese analogue was developed using dry-fractionated pea protein and an emulsion-filled gel composed of extra virgin olive oil and inulin, added in different concentrations as fat replacer (10%, 13% and 15% of the formulation). First, nutritional and textural analyses were performed, and the results were compared with two commercial products. The products were high in protein (134 g kg-1 ) and low in fat (52.2 g kg-1 ). The formulated PCAs had similar spreadability index to the dairy cheese but lower hardness (15.1 vs. 19.0 N) and a higher elasticity (0.60 vs. 0.35) consequent to their lower fat content (52.2 vs. 250 g kg-1 ). Then, dry oregano and rosemary (5 g kg-1 ) were added to the PCA, and sensory evaluation and analysis of volatile compounds were conducted. The addition of spices masked the legume flavor and significantly enriched the final product with aromatic compounds. CONCLUSION: The use of dry-fractioned pea protein and of the emulsion-filled gel allowed us to develop a clean label and nutritionally valuable spreadable plant-based cheese analogue. Overall, the ingredients and product concepts developed could be used to upgrade the formulation of plant-based cheese on a larger scale. © 2022 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Optimization of formulation and physicochemical, nutritional and sensory evaluation of vegan chickpea-based salad dressings.

The formulation of a vegan salad dressing supplemented with chickpea flour (VC-SD) was optimized by D-optimal mixture design, evaluating the effect of chickpea flour, water and oil on the textural properties of the product. The linear models showed the best fitting and predictive ability, as highlighted by high R2 adj and Q2. The Cox-effects of the textural parameters were significant for water and chickpea flour contents, but not for oil. Sensory evaluation indicated that all the VC-SD were characterized by the predominance of pungent/acid odor notes, whereas sourness was the most perceived fundamental taste, together with a sensation of a grainy texture in mouth due to flour particles. Overall, the product can be consumed by vegans and vegetarians because produced without animal-derived ingredients, and is in synergy with the healthful characteristics of Mediterranean diet, in which pulses and extra-virgin olive oil play beneficial roles. Supplementary Information: The online version contains supplementary material available at 10.1007/s13197-021-05288-x.

Kabuli and Apulian black Chickpea Milling By-Products as Innovative Ingredients to Provide High Levels of Dietary Fibre and Bioactive Compounds in Gluten-Free Fresh Pasta.

Gluten-free (GF) products, including pasta, are often characterised by nutritional deficiencies, such as scarce dietary fibre and excess of calories. Chickpea flour is increasingly being used by the food industries. Hulls, rich in dietary fibre and bioactive compounds, are discarded after milling. The aim of this work was to evaluate the quality features of short-cut GF fresh pasta added of hull (8% w/w) derived from kabuli (KH) or Apulian black (ABH) chickpeas, in comparison with control GF pasta prepared without hull. The enriched pasta, which could be labelled as "high fibre", was characterised by a higher level of bioactive compounds and antioxidant activity than the control. ABH-enriched pasta showed the highest anthocyanins (33.37 ± 1.20 and 20.59 ± 0.11 mg/kg of cyanidin-3-O-glucoside on dry matter in raw and cooked pasta, respectively). Hull addition increased colour intensity and structural quality of GF pasta: ABH-enriched pasta had the lowest cooking loss and the highest water absorption capacity; KH-enriched pasta showed the highest firmness. No significant differences in sensory liking were found among the samples, except for "aftertaste". Chickpea hull can be used as an innovative ingredient to produce potentially functional GF pasta, meeting the dietary needs of consumers without affecting quality.

Supercritical CO2 Extraction of Phytocompounds from Olive Pomace Subjected to Different Drying Methods.

Olive pomace is a semisolid by-product of olive oil production and represents a valuable source of functional phytocompounds. The valorization of agro-food chain by-products represents a key factor in reducing production costs, providing benefits related to their reuse. On this ground, we herein investigate extraction methods with supercritical carbon dioxide (SC-CO2) of functional phytocompounds from olive pomace samples subjected to two different drying methods, i.e., freeze drying and hot-air drying. Olive pomace was produced using the two most common industrial olive oil production processes, one based on the two-phase (2P) decanter and one based on the three-phase (3P) decanter. Our results show that freeze drying more efficiently preserves phytocompounds such as α-tocopherol, carotenoids, chlorophylls, and polyphenols, whereas hot-air drying does not compromise the ß-sitosterol content and the extraction of squalene is not dependent on the drying method used. Moreover, higher amounts of α-tocopherol and polyphenols were extracted from 2P olive pomace, while ß-sitosterol, chlorophylls, and carotenoids were more concentrated in 3P olive pomace. Finally, tocopherol and pigment/polyphenol fractions exerted antioxidant activity in vitro and in accelerated oxidative conditions. These results highlight the potential of olive pomace to be upcycled by extracting from it, with green methods, functional phytocompounds for reuse in food and pharmaceutical industries.

Functional compounds from olive pomace to obtain high-added value foods - a review.

Olive pomace, the solid by-product from virgin olive oil extraction, constitutes a remarkable source of functional compounds and has been exploited by several authors to formulate high value-added foods and, consequently, to foster the sustainability of the olive-oil chain. In this framework, the aim of the present review was to summarize the results on the application of functional compounds from olive pomace in food products. Phenolic-rich extracts from olive pomace were added to vegetable oils, fish burgers, fermented milk, and in the edible coating of fruit, to take advantage of their antioxidant and antimicrobial effects. Olive pomace was also used directly in the formulation of pasta and baked goods, by exploiting polyunsaturated fatty acids, phenolic compounds, and dietary fiber to obtain high value-added healthy foods and / or to extend their shelf-life. With the same scope, olive pomace was also added to animal feeds, providing healthy, improved animal products. Different authors used olive pomace to produce biodegradable materials and / or active packaging able to increase the content of bioactive compounds and the oxidative stability of foods. Overall, the results highlighted, in most cases, the effectiveness of the addition of olive pomace-derived functional compounds in improving nutritional value, quality, and / or the shelf-life of foods. However, the direct addition of olive pomace was found to be more challenging, especially due to alterations in the sensory and textural features of food. © 2020 Society of Chemical Industry.

The challenge of exploiting polyphenols from olive leaves: addition to foods to improve their shelf-life and nutritional value.

Olive leaves represent a waste from the olive oil industry which can be reused as source of polyphenols. The most representative phenolic compound of olive leaves is the secoiridoid oleuropein, followed by verbascoside, apigenin-7-O-glucoside, luteolin-7-O-glucoside, and simple phenols. The attention towards these compounds derives above all from the large number of studies demonstrating their beneficial effect on health, in fact olive leaves have been widely used in folk medicine in the Mediterranean regions. Moreover, the growing demand from consumers to replace the synthetic antioxidants, led researchers to conduct studies on the addition of plant bioactives in foods to improve their shelf-life and/or to obtain functional products. The current study overviews the findings on the addition of polyphenol-rich olive leaf extract (OLE) to foods. In particular, the effect of OLE addition on the antioxidant, microbiological and nutritional properties of different foods is examined. Most studies have highlighted the antioxidant effect of OLE in different food matrices, such as oils, meat, baked goods, vegetables, and dairy products. Furthermore, the antimicrobial activity of OLE has been observed in meat and vegetable foods, highlighting the potential of OLE as a replacer of synthetic preservatives. Finally, several authors studied the effect of OLE addition with the aim of improving the nutritional properties of vegetable products, tea, milk, meat and biscuits. Advantages and drawbacks of the different use of OLE were reported and discussed. © 2020 Society of Chemical Industry.

Effects of storage on the oxidative stability of acorn oils extracted from three different Quercus species.

BACKGROUND: Acorn fruit and its components and by-products are receiving renewed interest due to their nutritional and phytochemical features. In particular, the oil extracted from acorns is recognized for having high nutritional quality and for being rich in bioactive compounds. Despite the growing interest, few papers are available that consider the evolution of acorn-oil characteristics during storage. Our aim was to investigate the storage-related changes in acorn oils extracted from three Quercus species grown in Algeria (Q. ilex, Q. suber, and Q. coccifera) 180 days after production, with a focus on polar and volatile compounds, not yet investigated. Basic quality parameters, phenolic content, antioxidant activity and induction time were also monitored. RESULTS: The oxidation markers (peroxide value and UV absorptions) increased during storage, whereas antioxidants decreased. A distinctive volatile profile was observed at the time of production, which underwent changes during storage. Polar compounds increased, whereas induction time decreased. The oil extracted from Quercus suber L. was the most affected by storage time. CONCLUSION: Floral and fruity volatile compounds detected in the oils' headspace could explain the pleasant flavor of acorn oils reported by other authors. As with other vegetable oils, storage depletes both volatiles and antioxidants and produces oxidation compounds, such as oxidized triacylglycerols. However, the acorn oils that were studied were quite stable under storage in the dark at room temperature for 6 months. © 2020 Society of Chemical Industry.

Phenolic extracts from whole wheat biofortified bread dampen overwhelming inflammatory response in human endothelial cells and monocytes: major role of VCAM-1 and CXCL-10.

PURPOSE: The aim of the study was to evaluate the vascular health properties of extracts from biofortified bread, obtained by adding different durum wheat milling by-products rich in phenolic compounds, by analyzing their effects on overwhelming inflammatory response in endothelial cells and monocytes, two main players of atherogenesis. METHODS: Human umbilical vein endothelial cells or U937 monocytes were incubated with increasing concentrations (1, 5, 10 µg/mL) of biofortified bread polyphenol extracts or corresponding pure phenolic acids before stimulation with lipopolysaccharide (LPS). We analyzed the endothelial-monocyte adhesion and related endothelial adhesion molecules. The expression of chemokines and pro-inflammatory cytokines was also measured in LPS-stimulated endothelial cells and monocytes as well as intracellular oxidative stress. RESULTS: Biofortified bread extracts inhibited monocyte adhesion to LPS-stimulated endothelial cells, in a concentration-dependent manner by reducing mainly endothelial VCAM-1 expression. Phenolic acid extracts contained in 10 mg biofortified bread downregulated the LPS-induced expression of chemokines MCP-1, M-CSF, and CXCL-10 as well as pro-inflammatory cytokines TNF-α and IL-1ß, in endothelial cells and monocytes, with CXCL-10 as the most reduced inflammatory mediator. Among phenolic acids of biofortified bread, ferulic, sinapic, and p-coumaric acids significantly inhibited the LPS-stimulated CXCL-10 expression in vascular cells. The reduced pro-inflammatory response was related to a slightly but significant reduction of intracellular oxidative stress. CONCLUSIONS: Our findings suggest the bread biofortified with selected durum wheat milling by-products as a source of phenolic acids with multiple anti-inflammatory and anti-atherosclerotic properties, which could help to counteract or prevent inflammatory vascular diseases.

Evaluation of total phenolic content in virgin olive oil using fluorescence excitation-emission spectroscopy coupled with chemometrics.

BACKGROUND: Determination of the total phenolic content (TPC) in olive oils is of great interest, as phenolic compounds affect the health benefits, sensory attributes and oxidative stability of olive oils. The aim of this study was to explore the feasibility of direct front-face fluorescence measurements coupled with chemometrics for developing multivatiate models for discrimination between virgin olive oils with low and high TPC and determination of TPC concentration. RESULTS: Parallel factor analysis and principal component analysis of fluorescence excitation-emission matrices (EEMs) of virgin olive oils revealed different fluorescent properties for samples with low and high TPC. A perfect discrimination of oils with low and high TPC was achieved using partial least squares (PLS) discriminant analysis. The best regression model for the prediction of TPC was based on the PLS analysis of the unfolded entire EEMs (R2  = 0.951, RPD = 4.0). CONCLUSIONS: The results show the potential of fluorescence spectroscopy for direct screening of virgin olive oils for TPC. This may contribute to the development of fast screening methods for TPC assessment, providing an alternative to conventional assays. The procedure is environmentally friendly and fulfils the requirements for green analytical chemistry. © 2018 Society of Chemical Industry.

Physical and chemical behaviour of Nabali Mohassan single-cultivar olive oil during prolonged storage.

BACKGROUND: The effect of storage time on the fluorescence emission intensity and physico-chemical properties of olive oil from the Palestinian cultivar Nabali Mohassan was investigated. Olive oil samples stored up to 7 years were obtained from different olive orchards in Palestine, where prolonged storage is still in use. RESULTS: As a result of oxidation, all fluorescent minor compounds (tocopherols, chlorophylls, pheophytins and phenolic compounds) of olive oil significantly decreased as the storage time increased, whereas viscosity increased (P < 0.05). Until 1 year of storage, the physico-chemical properties of olive oil samples were within the limits of both Palestinian and European quality standards, and minor compounds, although affected by a marked decrease compared to freshly produced oil, were still detectable. After 5 years, a 90% decrease of the fluorescence attributed to tocopherols occurred and, after 7 years, phenolics reached a loss of 90%. CONCLUSION: The analysis of fluorescence, together with other physical measures, was demonstrated to be a useful tool for monitoring oil aging. This is the first report on fluorescent minor compounds of oils obtained from Nabali Mohassan olive cultivar. A better knowledge of this single-cultivar oil could enhance the adoption of the best practices by producers, improving the whole production chain. © 2018 Society of Chemical Industry.

Evaluation of the chemical and nutritional characteristics of almonds (Prunus dulcis (Mill). D.A. Webb) as influenced by harvest time and cultivar.

BACKGROUND: Several workers have studied the effect of harvest time on chemical and nutritional composition of almonds, but the results are partly conflicting, probably due to differences in the cultivars considered and to different agronomic and climatic conditions in the growing areas. In this paper, the influence of harvest time and cultivar on the chemical and nutritional composition of almonds (Prunus dulcis (Mill). D.A. Webb) were evaluated. Ten cultivars were considered, grown in the same orchard and subjected to the same agronomical regime. Almonds were collected at two different harvest times: (i) when the fruits were unripe, but already edible, and showed green and moist hull; and (ii) when the fruits were ripe, with dry brown hull. The analyses of proximate composition, fatty acid profile, total phenolic compounds, and antioxidant activity were carried out. RESULTS: Lipid content increased (P < 0.001) during ripening, while both protein and carbohydrate content decreased (P < 0.01). Fatty acid composition showed a not univocal behavior during ripening and was highly influenced by cultivar. Total phenolic compounds and antioxidant activity varied among cultivars but increased during ripening with the exception of cv Marcona. The 'Genco' and 'Francolì' cultivars were found to be phenolic rich. CONCLUSION: Harvest time and cultivar significantly influenced the chemical and nutritional composition of almonds. Genotype strongly influenced fatty acid composition and total phenolic compounds. The changes of bioactive compounds and antioxidant activity suggest that the synthesis of antioxidants also occurs in the last stage of ripening. Unripe almonds, a valuable niche product, showed interesting nutritional value. © 2018 Society of Chemical Industry.

Influence of the feed pipe position of an industrial scale two-phase decanter on extraction efficiency and chemical-sensory characteristics of virgin olive oil.

BACKGROUND: Nowadays, olive oil extraction is basically achieved by means of two-phase decanters, which allow a reduction of water consumption and the leaching of phenolic compounds. Despite this, most of the working settings derive from studies carried out on three-phase decanters. Hence, the aim of the present study was to assess the influence of two-phase decanter feed pipe position (FP) on the extraction efficiency and chemical-sensory characteristics of virgin olive oil. Three different positions were considered: at 825 mm (FP1), 610 mm (FP2) and 520 mm (FP3) from the outlet of the oily phase. RESULTS: Position FP3 allowed the highest oil recovery (up to 10%), the lowest percentage of oil in the olive pomace and, in general, a regular trend in terms of oil extraction efficiency. However, the oily must that came out of the decanter was not completely clean in terms of residual content of solid sediment and water. The feeding position partially affected the profile of antioxidant compounds. CONCLUSION: In two-phase decanters, loading the olive paste close to the outlet of the oily phase is recommended to increase the extraction efficiency without jeopardizing the chemical-sensory characteristics of virgin olive oil. © 2018 Society of Chemical Industry.

Polyphenol Oxidases in Crops: Biochemical, Physiological and Genetic Aspects.

Enzymatic browning is a colour reaction occurring in plants, including cereals, fruit and horticultural crops, due to oxidation during postharvest processing and storage. This has a negative impact on the colour, flavour, nutritional properties and shelf life of food products. Browning is usually caused by polyphenol oxidases (PPOs), following cell damage caused by senescence, wounding and the attack of pests and pathogens. Several studies indicated that PPOs play a role in plant immunity, and emerging evidence suggested that PPOs might also be involved in other physiological processes. Genomic investigations ultimately led to the isolation of PPO homologs in several crops, which will be possibly characterized at the functional level in the near future. Here, focusing on the botanic families of Poaceae and Solanaceae, we provide an overview on available scientific literature on PPOs, resulting in useful information on biochemical, physiological and genetic aspects.