The objective of the present study was to evaluate the effect of three common cooking practices (i.e., boiling, steaming, and frying) on phytochemical contents (i.e., polyphenols, carotenoids, ...glucosinolates, and ascorbic acid), total antioxidant capacities (TAC), as measured by three different analytical assays Trolox equivalent antioxidant capacity (TEAC), total radical-trapping antioxidant parameter (TRAP), ferric reducing antioxidant power (FRAP) and physicochemical parameters of three vegetables (carrots, courgettes, and broccoli). Water-cooking treatments better preserved the antioxidant compounds, particularly carotenoids, in all vegetables analyzed and ascorbic acid in carrots and courgettes. Steamed vegetables maintained a better texture quality than boiled ones, whereas boiled vegetables showed limited discoloration. Fried vegetables showed the lowest degree of softening, even though antioxidant compounds were less retained. An overall increase of TEAC, FRAP, and TRAP values was observed in all cooked vegetables, probably because of matrix softening and increased extractability of compounds, which could be partially converted into more antioxidant chemical species. Our findings defy the notion that processed vegetables offer lower nutritional quality and also suggest that for each vegetable a cooking method would be preferred to preserve the nutritional and physicochemical qualities.
No literature data were available on the crystal polymorph structure associated with the crystallization/melting of TAG fractions of extra virgin olive oil until the publication of the article by ...Barba, Arrighetti and Calligaris in this issue of the European Journal of Lipid Science and Technology p. 322–329. The authors determined crystal structure of extra virgin olive oil TAGs using DSC coupled with XRD technique. These findings are of great importance as an increasing number of formulated foods (e.g. salad dressings, sauces, chilled and frozen ready‐to‐eat products) and new products are nowadays produced with this high quality vegetable oil as lipid phase. The significance of these results is underlined in this commentary.
See accompanying article by Barba et al. p. 322–329, http://dx.doi.org/10.1002/ejlt.201200259
In breadmaking, dietary fibres are used to improve the nutritional quality of the final products; on the other hand, they may affect the physical and sensory properties. This work aimed to the ...evaluate, on pan breads, the effect of substituting 3 g of wheat flour with an equivalent amount of fibre rich ingredients: chestnut peels (CP) or wheat bran (WB), in comparison to a traditional wheat bread formulation (C). The effect of four levels of added water (54, 60, 66, 71 g/100 of flour) was also tested. The fibre content of CP (33%) and WB (42%) affected their water binding capacity and, consequently, the quality of the final loaves, according to the different water addition levels. In bread crumb, water content and water activity increased proportionally to the water addition levels, being instead in the crust also affected by the presence of fibres: lower water retention capacity was observed for CP, in comparison to WB and C. The loaf volume resulted higher for C in comparison to WB and CP, in relation to the larger dimensions of the crumb pores, probably due to the interfering effect of fibres during the development of the gluten network. Crumb hardness resulted higher for C at low water addition levels, being instead higher for CP at high water addition levels. CP showed a darker and redder colour, than both WB and C bread, for the presence of the brown pigments carried by chestnut peels. PCA analysis confirmed that more water is required for both the fibre-enriched breads to show characteristics similar to the control loaves.
A distinguishing quality or characteristics of apple puree was determined considering the effect of different processing practices: thermal (4 T), ohmic heating (OHM) and high-pressure processing ...(HPP). In the thermal treatment, the flow rate was set to 1700 L/h and SHP was approximately 40 s; HPP was conducted at 600 MPa for 3 min and ohmic heating at a flow rate of 2000 L/h, at 107 °C (sample preheated from 25 to 60 °C). Effects on colour, viscosity, particle size distribution (PSD), total phenol content (TPC), ascorbic acid content and sensorial quality were comparatively studied. Results showed that a very low reduction of ascorbic acid in HPP is observed. The highest ascorbic acid loss was observed for 4 T and in a lower extent for OHM ascribable to the thermal degradation, as hypothesized for pigments. The TPC content was not changed during processing. The other quality parameters evaluated (viscosity, colour, PSD, turbidity, consistency, sensorial analysis) were affected by treatments, with particular reference to 4 T. This is one of the first study applying commercial industrial-scale equipment’s. Concluding, as compared to 4 T, OHM and HPP demonstrated feasible technologies for the treatment of apple puree, having obtained also a good organoleptic response. Apple purée preparation by means of high-pressure processing, ohmic or mild thermal treatments could imply new opportunities for the apple processing industry in developing more fresh like value-added products with reasonable shelf life.
► Tomatoes were harvested at two ripening stages and let to ripe with or without UV-B. ► UV-B treatment increased carotenoid and ascorbic acid content in Money maker fruits. ► Irradiated fruits of ...high pigment-1 showed very few changes in nutraceutical content. ► Colour parameters were more influenced by harvesting stage than UV-B treatment. ► Fruit firmness was negatively affected by UV-B irradiation in both genotypes.
Nutraceutical (ascorbic acid and carotenoids) and physical (colour and firmness) parameters were evaluated in two tomato genotypes (Money maker and high pigment-1) subjected to post harvest UV-B irradiation at different ripening stages (mature green and turning).
UV-B treatment increased the concentration of ascorbic acid and carotenoids in Money maker flesh and peel, while high pigment-1 fruits underwent only minor changes, suggesting that hp-1 mutation decreased the fruit ability to respond to UV-B radiation. Colour parameters appeared to be more influenced by harvesting stages than UV-B with the exception of redness (a∗), which in Money maker was found to increase in both flesh and peel of irradiated fruits at turning stage, although not significantly, while control was more red than treated at mature green stage. Firmness was negatively influenced by UV-B, as tomatoes were found to soften after the treatment, although this aspect needs further studies to be clarified.
This study evaluated the effect of common cooking practices (i.e., boiling, microwaving, and basket and oven steaming) on the phytochemical content (carotenoids, chlorophylls, glucosinolates, ...polyphenols, and ascorbic acid), total antioxidant capacity (TAC), and color changes of three generally consumed Brassica vegetables analyzed fresh and frozen. Among cooking procedures, boiling determined an increase of fresh broccoli carotenoids and fresh Brussels sprout polyphenols, whereas a decrease of almost all other phytochemicals in fresh and frozen samples was observed. Steaming procedures determined a release of polyphenols in both fresh and frozen samples. Microwaving was the best cooking method for maintaining the color of both fresh and frozen vegetables and obtaining a good retention of glucosinolates. During all cooking procedures, ascorbic acid was lost in great amount from all vegetables. Chlorophylls were more stable in frozen samples than in fresh ones, even though steaming methods were able to better preserve these compounds in fresh samples than others cooking methods applied. The overall results of this study demonstrate that fresh Brassica vegetables retain phytochemicals and TAC better than frozen samples.
Cocoa bean shells (CBS) are by-products of cocoa processing. Their rich chemical composition makes them interesting ingredients to improve the overall quality of gluten free bread. The addition of ...different dimensional fractions (F1, 1.00–1.99 mm; F2, 0.50–0.99 mm; F3, 0.355–0.49 mm) of CBS to gluten-free bread was investigated in terms of volume, moisture content, crumb grain, texture and colour during 3 days of storage. No significant differences in moisture content were observed among fractions, but protein, fat and fibre content resulted influenced by the dimensional range. With reference to water absorption indexes, F2 showed the highest water binding capacity (WBC) and water holding capacity (WHC), having instead the lowest water solubility index (WSI), in comparison with the other fractions, and confirming a good retention of the fibres’ structure. Results on bread showed that CBS addition modified crumb grain leading to a lower specific volume, especially for F2. The presence of CBS accelerated significantly the crumb staling process in comparison with the control, resulting; however, F1 softer than control at the end of the storage period. Finally, colour was improved by the presence of CBS becoming darker, with F3 showing the highest impact on
L*
and
a*
.
In this work, the impact of the industrial freezing process on structure, texture and total antioxidant capacity was studied using green asparagus stems, zucchini and green beans. Samples were ...analysed as raw/uncooked, blanched, raw/boiled and industrially frozen/boiled.
A consistent damage of the vegetable tissue was revealed by the histological analysis on vegetables boiled after freezing. The cells appeared to be dehydrated, contracted and separated at different levels depending on the anatomical structure of each vegetable.
The initial textural quality was partially retained in all blanched vegetables, and enhanced in cut tested asparagus stems, in relation to the action of phenolic acids at cell wall level. Raw/boiled and industrially frozen/boiled asparagus stems exhibited comparable forces of penetration and cut tests. On the other hand, zucchini, both raw and frozen, completely softened after boiling making the texture measurement impossible. Industrially frozen/boiled green beans showed higher values of cut and penetration forces, probably due to a higher presence of swollen cell walls, in comparison to those raw/boiled.
Blanching and boiling significantly increased the ferric reducing antioxidant power values of asparagus stems and green beans compared to uncooked/raw samples, while boiling after the freezing process significantly deprived both vegetables of the initial antioxidant capacity. On the other hand, boiling the frozen zucchini proved to be detrimental to the antioxidant capacity.
In conclusion, manufacturers and researchers should join together to develop specific industrial freezing process conditions according to the matrix of each vegetable.
•The impact of the industrial freezing process on selected vegetables is presented•Frozen boiled vegetables exhibit significant cell damage•A different retention of textural quality in processed vegetables is obtained•Frozen boiled vegetables show the lowest antioxidant capacity•Development of specific process conditions according to vegetable matrix is required
This study aimed to investigate the gelling behavior of faba bean (FB) and chickpea (CP) flour between 10 and 20% (
) concentration at pH 3.0, 5.0, and 7.0. Both sources formed at pH 3.0 and 5.0 ...self-standing gels with 12% (
) of flour, while 16% (
) of flour was required to obtain a gel at pH 7.0. During gelling between 40 and 70 °C, a sharp increase of the elastic modulus G' was observed in both flours, mainly due to water absorption and swelling of the starch, one of the major constituents in the ingredients. Increasing the temperature at 95 °C, G' increased due to the denaturation of globulins and therefore the exposure of their internal part, which allowed more hydrophobic interactions and the formation of the gel. After cooling, both FB and CP gels displayed a solid-like behavior (tan δ ranging between 0.11 and 0.18) with G' values at pH 3.0 and 5.0 significantly (
< 0.05) higher than those at pH 7.0, due to the lower electrostatic repulsions at pHs far from the isoelectric point. The rheological properties were supported by the water binding capacity values, confirming the better gels' strength described by rheological analysis. These results will enhance our understanding of the role of legume flours in formulating innovative and sustainable food products as alternatives to animal ones.
In the present study, the possibility of enhancing phenolic and flavonoid concentration in tomato (Solanum lycopersicum L.) fruits by post-harvest irradiation with UV-B light was assessed. Fruits of ...the commercial cv Money Maker (MM) and the mutant genotype high pigment-1 (hp-1), constitutively rich in these compounds, were harvested at mature green and turning stages and left to ripen within climatic chambers where they were daily treated with UV-B radiation (1 h, 6.08 kJ/m² day). In control chambers, UV-B radiation was screened by benzophenone-treated polyethylene film. The treatment was generally effective in increasing phenolic, flavonoid and flavonol concentration in both peel and flesh of MM and hp-1 fruits, although in this latter the positive response to UV-B treatment was mainly evident in fruits harvested at mature green stage. Following UV-B treatment, antioxidant activity increased in the peel of both genotypes independently from the harvesting stage and in the flesh of hp-1 fruits harvested at mature green stage. Hydroxycinnamic acids of both genotypes reacted to UV-B treatment differently depending on harvesting stage and tissue localisation, generally showing an increase in the peel of fruits harvested at mature green stage. With few exceptions, UV-B irradiation also induced a higher accumulation of individual flavonoids both in the peel and in the flesh of MM and hp-1 fruits independently from harvesting stage. Based on these results, UV-B irradiation can be considered a promising technique to increase the nutraceutical potential of tomato fruits by non-molecular tools.
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