•Grape pomace from Portuguese cultivars was targeted as source of polyphenolic compounds.•An environmental-friendly extract with polyphenols was obtained.•Extracts showed bioactive properties in ...radical scavenging and iron(II) chelating assays.•“Touriga Nacional” grape cultivar showed the highest potential for industrial applications.
Grape pomace can be regarded as an excellent and affordable source of polyphenolic compounds. Hence, the main objective of this work was to conduct a comparative study of different Portuguese grape varieties, using an extraction methodology with possible applications in sustainable agriculture and pest management. Scavenging capacity against DPPH, oxygen radical absorbance capacity (ORAC), iron(II) chelating ability (ICA) and Folin–Ciocalteu assays were performed in order to evaluate the antioxidant capacity profile and total phenolic content (TPC) in ethanol/water extracts and aqueous grape pomace suspensions. Strong significant correlation between TPC and DPPH (R=0.944), and a low correlation between ORAC and the other assays was obtained (R≤0.632). ICA was not correlated with any of the other assays (R≤0.263). All grape pomace extracts have presented high antioxidant properties (ORAC) and chelating ability, ranging from 906 to 2337μmol TEg−1 residue and from 55 to 104 % inhib. mg−1 residue, respectively. Results from HPLC analysis showed the presence of gallic acid, caffeic acid, syringic acid, (+)-catechin and (−)-epicatechin being syringic acid and (+)-catechin the major compounds. Although further studies are required, “Touriga Nacional” was the most promising grape cultivar regarding its highest values for TPC (142.4±1.1mg GAEg−1 dry residue), DPPH (1.12±0.04 mmol TEg−1 dry residue) and ORAC (1579±244μmol TEg−1 dry residue) assays. Since Portugal is a major wine producer, utilization of pomace generated during the wine elaboration steps opens a new trend toward a simple and relatively easy compounds extraction with high antioxidant activity in order to contribute to emerging industrial applications and sustainable agriculture.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Dietary inclusion of IMTA-cultivated
Gracilaria vermiculophylla
was evaluated in rainbow trout. Growth and feed efficiency were determined in fish fed 0 % (CTRL), 5 % (G5), and 10 % (G10) of the red ...seaweed for 91 days. Carotenoid concentration (skin and muscle), immunological parameters, and intestinal morphology were also evaluated. G10 group showed the lowest final body weight, with feed and protein efficiency ratios being significantly lower than the CTRL. Although protein intake was similar among groups, G10 diet induced the lowest protein retention and gain probably due to its smallest intestine diameter and lowest
villi
height. Fish fed G10 diet displayed higher carotenoid content in the skin (16.7 μg g
−1
) when compared with the CTRL group, but a lower concentration was registered in the flesh (0.23 μg g
−1
). Instrumental color showed that fillets were more luminous (
L
*), less yellowish (
b
*), and more reddish (a*) with seaweed inclusion and the lowest chrome intensity (
C
*) in the G10 group confirmed the lowest muscle carotenoid content in these fish. G5 diet enhanced the innate immune response of rainbow trout inducing the highest peroxidase, alternative complement (ACH50), and lysozyme activities. The inclusion of
Gracilaria
meal in diets for rainbow trout is possible up to 5 %, but a higher inclusion level impairs growth.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
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•The Rate-All-That-Apply (RATA) approach increased the percentage of selected terms.•RATA approach allowed to discriminate females according to their origin.•Sea urchin gonads’ ...sensory properties changed with sex.•Females were more appealing than males.•Males had a slimy appearance and a milky white exudate.
Paracentrotus lividus gonads are receiving increasing interest for their unique sensory attributes. However, the sensory profile of this highly demanded gourmet product has not yet been well described, and doing so may potentially benefit the gonads’ marketability and acceptability. The main goal of this study was to build a sensory profile of sea urchin (Paracentrotus lividus) gonads, to evaluate differences between sex and harvest location. Eighty untrained panellists (regular consumers of seafood) were asked to evaluate four samples of raw sea urchin gonads (inside a sea urchin test), divided by sex and harvest location. The panellists evaluated overall liking and acceptance (Food Action Scale), followed by a Rate-All-That-Apply (RATA) ballot with a list of 22 sensory attributes divided into four dimensions: appearance (6), odour (6), texture (4) and taste (6). No significant effects of sex and harvest location were identified for liking, but a significant effect of the sex for the Food Action Rating Scale (FACT) was identified. Sensory profiling clearly separated gonads according to sex, with females being more appealing than males. Females were strongly correlated with a pleasant and intense tropical taste, as well as an overall appealing and grainy appearance and a pleasant tropical odour, while males had a slimy appearance and a milky white exudate. When compared with the Check-All-That-Apply (CATA) approach used in our previous study, the use of the RATA approach allowed to discriminate female gonads according to their origin, with those from Praia Norte being firmer, more resilient and more appealing than the ones from Carreço. This study reinforced the fact that female sea urchins tend to present an intense and pleasant tropical taste and a pleasant tropical odour, thus being more appealing to the panellists, contributing valuable information for future nutritional aquaculture studies aiming to enhance sea urchin gonads’ attributes and, subsequently, their market valorisation.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
•Food waste on school lunch is affected by individual, social and environmental factors.•The presence of teachers during the meal period is associated with low plate waste.•Mid-morning snacks ...influence food waste at the school canteen.•Meals sensory characteristics satisfaction influences food waste at the school canteen.
This study aims to explore the factors that influence plate waste at lunches served in primary schools. Data was collected for all fourth-grade children attending 21 primary schools from the city of Porto (Portugal) (n = 463). Plate waste was evaluated by the weighing method and factors influencing plate waste were collected by observation of menu and canteen characteristics and through the application of a questionnaire to children aiming to evaluate factors related to preferences and dietary patterns. Logistic regression was performed to identify predictors of plate waste. It was observed that fish menus and composed dishes showed a higher tendency for increased plate waste. However, this effect was not observed when adjusted for other variables. Soups without pulses and blended soups were less likely to be discarded by children. The presence of the teacher during meals and the possibility for children to leave the canteen whenever they wish, protected both the main dish and the soup from being wasted. A higher number of children in the canteen was associated with increased soup waste. As expected, children more pleased with the sensory characteristics of the main dish and soup were less likely to waste food. Children who consumed high-saturated fat content mid-morning snacks were more likely to waste soup.
The main factors associated with plate waste were related to the presence of teachers during the mealtime, school meal policies and the meals’ sensory characteristics. Additionally, soup waste was determined by its composition, mid-morning snacks and the number of children in the canteen.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Background
Despite drought and nitrogen (N) deficit being two of the most important crops’ growth limiting factors, only few studies have explored tomato phenotypic variability in response to both ...abiotic stresses.
Aims
In this study, we aimed to perform a phenotypic evaluation and an analysis of the growth traits of 40 tomato genotypes (mostly focusing on old cultivars, but also including modern hybrids and wild tomato relatives’ accessions as anchors) grown in pots that were subjected to combined N and water deficit.
Methods
Each genotype was divided into two groups: control (100% N, 100% field capacity) and combined deficit (20% N, 50% field capacity). A total of 14 morpho-physiological traits were evaluated and further analyzed using multivariate statistical methods.
Results
The Principal Component Analyses revealed considerable phenotypical diversity among tomato genotypes, with four principal components explaining 82% of the variability. Data integration on a cluster analysis separated the studied genotypes into three distinct clusters based on their ability to handle the combined deficit. Tolerance was associated with traits such as lower specific leaf area, lower leaf area ratio and higher water use efficiency, comparing to the sensitive genotypes.
Conclusions
This study shows that tomato tolerance to combined N and water deficit largely varies between genotypes and that old cultivars represent a valuable gene pool towards more sustainable food production systems.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
A series of pyridyl analogues of rosamines was prepared by employing two methodologies: (i) the conventional‐heating condensation of a pyridinecarboxaldehyde with 3‐(diethylamino)phenol in propionic ...acid, and (ii) the novel ohmic‐heating assisted condensation under “on water” conditions, followed by oxidation. The 4‐pyridyl substituted rosamine was further converted into the N‐methylpyridinium derivative through N‐alkylation using methyl iodide. The influence of the position and cationization of the nitrogen atom of the pyridyl ring in the physicochemical properties of fluorophores was investigated by 1H, 13C, 15N NMR spectral analysis, UV/Vis and fluorescence spectroscopy, single‐crystal X‐ray diffraction (4‐pyridyl and N‐methylpyridinium derivatives) and thermal‐behavior analysis. Curiously, for ethanolic solutions of 4‐pyridyl and N‐methylpyridinium derivatives an extinction of color and fluorescence over time was observed. This phenomenon was further studied and the data revealed that it is the result of nucleophilic addition of ethoxide ion to the central 9‐position of the xanthene. The kinetics of the process is slower for the 4‐pyridyl rosamine, which emphasizes the importance of the charge in the N‐methylpyridinium analogue in the reactivity of the molecule towards a nucleophile agent. This phenomenon is reversible, meaning that the compounds can be rapidly recovered by decreasing the pH, opening new avenues in the sensing applications of this class of rosamines.
Pyridyl and N‐methylpyridinium analogues of rosamines: The ohmic‐heating approach to synthesize triarylmethane derivatives, followed by oxidative cyclization, is presented. The influence of the position and cationization of the nitrogen atom in the pyridyl ring was evaluated by photophysical and thermal behavior analysis. In addition, the quenching behavior of the highly reactive N‐methylpyridinium rosamine in ethanol is reported for the first time.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
•High plate waste values at primary school canteens.•The visual estimation method is not as accurate as the weighing method.•The visual estimation method overestimated values of plate waste.•Wide ...variation on initial servings introduces a relevant bias for plate waste assessment.
The aim of this study was to validate the visual estimation method for aggregated plate waste of main dish at Portuguese primary school canteens. For this purpose plate waste at school lunch was measured for 505 individual servings, using weighing individual servings and plate waste and visual estimation method by a 6-point scale, as developed by Comstock et al. (1981). A high variability of initial serving weights was found with serving sizes ranging from 88.9 to 283.3g and with a coefficient of variation ranging from 5.5% to 24.7%. Mean plate waste was 27.5% according to the weighing method. There was a significant bias in the conversion of the visual waste estimations to actual waste, being overestimated by an average of 8.0g (ranging from −12.9g to 41.4g). According to Bland and Altman plot, the mean difference between methods was of 8.0g and the amplitude interval was 102.6g. The study showed that the visual estimation method is not as accurate as the weighing method in assessing nonselective aggregated plate waste at primary school canteens. Our findings are thus very important on considering plate waste assessment, since the wide variation on initial servings introduces a relevant bias when considering standard portions or a random sample of initial servings. Although, greater convenience, time-saving and the possibility to monitor plate waste of large groups, make the visual estimation method an important method to assess plate waste at school canteens, these results highlighted the need of portions standardization and control of initial servings to allow for its use.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
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•Sea urchin gonads’ sensory properties change with sex.•The presentation mode affected the sensory perception of sea urchin gonads.•There is an interaction effect between sea urchins’ ...sex and presentation mode.•Presentation in shell was correlated with a fresh, tropical and pleasant odour.•An orange and appealing sea urchin gonad, presenting a fresh odour is preferable.
Sea urchin gonads are receiving increasing attention for their exclusive sensorial attributes. However, the sensory profile of this highly demanded gourmet product has not yet been well described, and it may potentially help enhancing the gonads’ marketability and acceptability. The main goal of this study was to build a sensory profile of sea urchin (Paracentrotus lividus) gonads, to evaluate differences between sex, harvest location, as well as the impact of presentation on consumer acceptance. Sixty untrained panellists (regular consumers of seafood) were asked to evaluate eight samples of raw sea urchin gonads, divided by sex, harvest location and presentation (in a clear translucent glass bowl or inside a sea urchin test). The panellists evaluated overall liking and acceptance (Food Action Scale), followed by a Check-All-That-Apply (CATA) ballot with a list of 38 sensory attributes divided into four dimensions: appearance (9), odour (8), texture (7) and taste (14), launched in Sense Gest. From a three-way ANOVA, no significant effect of sex, harvest location and presentation were identified for both liking and acceptance. However, a significant interaction between presentation and sex was identified: females with gourmet presentation were rated higher than females presented in a bowl; and males presented in a bowl were favoured in relation to gourmet presentation. Sensory profiling clearly separates gonads according to sex, with females being more appealing than males that presented a milky white fluid. Gonads were also separated according to the presentation method: the white background of the bowl seemed to highlight the orange colour of females; the gourmet presentation favoured the females in relation to the males, mainly because the male gonad colour and white-colour exudate were emphasized by the background of the sea urchin test. Moreover, the gourmet presentation in both sexes was correlated with a fresh, tropical and pleasant odour. This study concluded that sea urchin with an orange gonad and a sweet, fresh and tropical flavour is preferable, which will allow future nutritional research efforts to be focused on the enhancement of these gonad attributes.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Sugar sweetened beverages are one of the main sources of added sugar in the diet. Therefore, sugar reduction in these products could contribute to the prevention of various negative health ...conditions, such as obesity, diabetes and cardiovascular diseases. In this context, the present work aimed to study consumer sensory and hedonic perception towards sugar reduction in fruit nectars. Five sequential difference thresholds for added sugar in three fruit nectars (passion fruit, orange/passion fruit and orange/pomegranate) were determined based on consumer perception. In each test, difference thresholds were estimated using survival analysis based on the responses of 50 consumers to six paired-comparison tests. Each pair was composed of two samples, a control nectar and a sample that was reduced in added sugar from the control. Consumers were asked to try each of the samples in each pair and to indicate which was sweeter. Then, consumers' sensory and hedonic perception of nectar samples was evaluated for each nectar using a 9-point hedonic scale and a check-all-that-apply question. Difference thresholds were estimated in 4.20%–8.14% of the added sugar concentration of the nectars. No significant differences in overall liking were detected for fruit nectars with 20% sugar reduction. However, large heterogeneity in consumer hedonic reaction towards sugar reduction was found, which should be taken into account in the design of sugar reduction programs. Consumer hedonic reaction towards sugar reduction was product dependent. Results from the present work reinforce the idea that gradual sugar reduction in sugar sweetened beverages is a feasible strategy that could contribute to reduce the sugar intake of the population.
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•Difference thresholds for added sugar in three fruit nectars were determined.•Consumers' hedonic reaction towards sugar reduction was product dependent.•Added sugar can be reduced 5–8% without affecting consumers' sensory perception•Reductions in the range of 10–20% did not lead to changes in hedonic reaction.•Heterogeneity in consumers' hedonic reaction towards sugar reduction was found.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
Increasing levels of a mixture of
Ulva
spp. (
Ulva rigida
and
Ulva lactuca
) produced in an integrated multi-trophic aquaculture (IMTA) system were evaluated in Nile tilapia. A control diet (CTRL) ...was compared with two experimental isonitrogenous (36 %) and isoenergetic (20 kJ g
−1
) diets containing 5 % (U5) and 10 % (U10) of
Ulva
spp. meal. Duplicate groups of 18 fish (255 g initial body weight) were reared at 25 °C and fed each diet for 68 days to evaluate carotenoid deposition, flesh organoleptic properties and immunological response. By the end of the trial, all groups of fish showed similar final body weight and specific growth rate. Whole body composition was also similar among treatments. The dietary incorporation of
Ulva
spp. meal increased total carotenoid content in the skin, with fish fed U5 displaying significantly higher levels (6.5 μg g
−1
) than the CRTL (1.4 μg g
−1
). No carotenoids could be found in tilapia muscle. Muscle colour determined using a spectrocolorimeter indicated that tilapia fillets from fish fed U10 showed the highest lightness (highest
L
* value) and yellowness (less negative
b
* value), but the lowest redness (lowest
a
* value). Furthermore, sensory attributes of flesh showed no significant effects of dietary treatments on visual, olfactory, texture and flavour parameters, with the exception of sour parameter that was lowest in U10-fed tilapia. The dietary inclusion of
Ulva
spp. meal had no beneficial effect on lysozyme or peroxidase activity, but the complement activity (ACH50), an important component of innate immune system in fish, increased concomitantly with the dietary inclusion level of
Ulva
spp. meal. The inclusion of
Ulva
spp. meal in diets for Nile tilapia seems to be possible up to 10 % without major effects on growth performance or flesh organoleptic properties but enhancing the innate immune response of the fish.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
