Betacyanins from Hylocereus polyrhizus: pectinase-assisted extraction and application as a natural food colourant in ice cream

The effect of solvent, substrate-to-solvent ratio and concentration of pectinase on the extraction of betacyanins from the pulp of red pitahaya (Hylocereus polyrhizus) was evaluated with respect to yield, betacyanin content (BC) and total sugar content. The application of betacyanins from red pitahaya in ice cream was then evaluated by comparison to a commercial colourant, E-162. Without the use of pectinase, the highest yields (9.11 ± 0.35%) of betacyanins were obtained using 95% ethanol at a substrate-to-solvent ratio of 1:1. With the use of pectinase at a concentration of 1.5%, the highest yield (17.11-17.45%) of betacyanins were obtained using water as a solvent at a substrate-to-solvent ratio of 1:1 and 1:2. Pectinase treatment (1.5-2.5%) using water as a solvent yielded betacyanins with the highest BC (126.47-130.83 g kg^-1) and lowest total sugar content (57.85-59.74 g kg^-1). The BC and total colour changes were similar in ice cream containing betacyanins from red pitahaya and E-162 throughout the 21-days of frozen storage at -18 °C. Betacyanins from red pitahaya or E-162 enhanced the antioxidant properties of ice cream. The sensory evaluation of ice cream containing betacyanins from red pitahaya showed a better colour acceptability than E-162.

Authentication of the geographical origin of Australian Cabernet Sauvignon wines using spectrofluorometric and multi-element analyses with multivariate statistical modelling

With the increased risk of wine fraud, a rapid and simple method for wine authentication has become a necessity for the global wine industry. The use of fluorescence data from an absorbance and transmission excitation-emission matrix (A-TEEM) technique for discrimination of wines according to geographical origin was investigated in comparison to inductively coupled plasma-mass spectrometry (ICP-MS). The two approaches were applied to commercial Cabernet Sauvignon wines from vintage 2015 originating from three wine regions of Australia, along with Bordeaux, France. Extreme gradient boosting discriminant analysis (XGBDA) was examined among other multivariate algorithms for classification of wines. Models were cross-validated and performance was described in terms of sensitivity, specificity, and accuracy. XGBDA classification afforded 100% correct class assignment for all tested regions using the EEM of each sample, and overall 97.7% for ICP-MS. The novel combination of A-TEEM and XGBDA was found to have great potential for accurate authentication of wines.

Color for the perceptual organization of the pictorial plane: Victor Vasarely's legacy to Gestalt psychology

Victor Vasarely's (1906-1997) important legacy to the study of human perception is brought to the forefront and discussed. A large part of his impressive work conveys the appearance of striking three-dimensional shapes and structures in a large-scale pictorial plane. Current perception science explains such effects by invoking brain mechanisms for the processing of monocular (2D) depth cues. Here in this study, we illustrate and explain local effects of 2D color and contrast cues on the perceptual organization in terms of figure-ground assignments, i.e. which local surfaces are likely to be seen as "nearer" or "bigger" in the image plane. Paired configurations are embedded in a larger, structurally ambivalent pictorial context inspired by some of Vasarely's creations. The figure-ground effects these configurations produce reveal a significant correlation between perceptual solutions for "nearer" and "bigger" when other geometric depth cues are missing. In consistency with previous findings on similar, albeit simpler visual displays, a specific color may compete with luminance contrast to resolve the planar ambiguity of a complex pattern context at a critical point in the hierarchical resolution of figure-ground uncertainty. The potential role of color temperature in this process is brought forward here. Vasarely intuitively understood and successfully exploited the subtle context effects accounted for in this paper, well before empirical investigation had set out to study and explain them in terms of information processing by the visual brain.

Optical changes of human dentin after non-vital bleaching and effect of Er,Cr:YSGG laser on micro-shear bond strength of a self-etch and an etch-and-rinse adhesive system

The aim was to evaluate the optical changes of bleached human dentin and the efficacy of Er,Cr:YSGG laser on micro-shear bond strength (μSBS) of two adhesive systems for immediate and delayed applications. Seventy-two human dentin specimens (1 mm) were obtained. Colour measurements of 30 specimens (control and bleaching groups) were made at baseline, after bleaching and a 7-day delay. Differences at colour (ΔE₀₀), translucency (ΔTP₀₀) and whiteness (ΔWI_D) were calculated by recorded data. Forty-two specimens were used to compare μSBS of a self-etch (Clearfil SE Bond [SE]) and an etch-and-rinse (Prime&Bond NT [PBNT]) adhesive to bleached dentin. Additional to a negative group, six groups were contemplated for each adhesive, considering the time of composite application (immediate, delayed) and whether additional surface treatment by laser (1 W, 2 W) or not. Colour and μSBS data were statistically analysed. For optical analysis, only ΔE₀₀ and ΔWI_D calculated for the difference between baseline and bleaching were found significantly different for control and bleaching groups. Whiteness of bleached specimens was remarkably decreased after a 7-day delay. Despite immediate applications of SE showing lower μSBS than negative control, delayed applications showed no significant differences except that of the 2 W laser etching. For PBNT, laser etching increased μSBS for both of the immediate and delayed applications, and no significant difference was observed from negative control. Related with the preferred adhesive system, Er,Cr:YSGG laser etching can be an alternative for optimal bond strength of immediate restorations, but the clinicians should always keep in mind that perceived colour and whiteness will change by the passing time which can affect the shade match.

Study of the role of oxygen in the evolution of red wine colour under different ageing conditions in barrels and bottles

Wine ageing in barrels is conditioned, among other factors, by the amount of oxygen received during this process, which thus impacts its final properties. The aim of this study was to evaluate the effect of oxygen on wine colour during ageing in barrels and bottles during different times. The use of barrels with different and known rates of oxygenation allows the effect of different oxygenation conditions throughout the process in barrels and its later evolution in bottles. A simulation process of ageing in bottles was used to study the impact of bottling in wines after differing ageing periods in barrels. The study of winés oxygen consumption capacity has been tied to colour modifications during ageing in barrels and bottles. Wines aged in barrels with a high oxygenation rate showed greater avidity to consume oxygen taking less time to consume that available, which is reflected in a greater increase in colour intensity.

Bliss is blue and bleak is grey: Abstract word-colour associations influence objective performance even when not task relevant

Humans associate abstract words with physical stimulus dimensions, such as linking upward locations with positive concepts (e.g., happy = up). These associations manifest both via subjective reports of associations and on objective performance metrics. Humans also report subjective associations between colours and abstract words (e.g., joy is linked to yellow). Here we tested whether such associations manifest on objective task performance, even when not task-relevant. Across three experiments, participants were presented with abstract words in physical colours that were either congruent with previously-reported subjective word-colour associations (e.g., victory in red and unhappy in blue), or were incongruent (e.g., victory in blue and unhappy in red). In Experiment 1, participants' task was to identify the valence of words. This congruency manipulation systematically affected objective task performance. In Experiment 2, participants completed two blocks, a valence-identification and a colour-identification task block. Both tasks produced congruency effects on performance, however, the results of the colour identification block could have reflected learning effects (i.e., associating the more common congruent colour with the word). This issue was rectified in Experiment 3, whereby participants completed the same two tasks as Experiment 2, but now matched congruent and incongruent pairs were used for both tasks. Again, both tasks produced reliable congruency effects. Item analyses in each experiment revealed that these effects demonstrated a degree of item specificity. Overall, there was clear evidence that at least some abstract word-colour pairings can systematically affect behaviour.

Influence of the carbonic maceration winemaking method on the physicochemical, colour, aromatic and microbiological features of tempranillo red wines

The aim of the study was to determine the differences in the microbiological, physical-chemical, aromatic and phenolic composition between two winemaking methods: carbonic maceration and the standard method of destemming and crushing. We analysed 84 commercial Rioja wines made from the Tempranillo grape variety during the 2017 vintage, 40 had been made by carbonic maceration and 44 by destemming and crushing. Despite the heterogeneity within the two groups of wines, it was possible to differentiate between them. Wines made by carbonic maceration presented higher aromatic quality due to their higher total content of esters and acetates, as well as a greater colour intensity due to a higher phenolic content and higher rates of ionization and polymerization. In addition, it was observed that the antioxidant activity, the content in coumaroyl derivatives of anthocyanins and the vitisins A and B were considerably greater in wines made by carbonic maceration.

Effect of cultivars, pretreatment and drying on physicochemical properties of Amla (Emblica officinalis) gratings

Effect of four different cultivars and salt pretreatment on drying of Amla (Emblica officinalis) gratings were studied. Quality attributes namely, ascorbic acid, total phenolic content, antioxidant activity and colour were evaluated for dried (using Cabinet tray dryer at 55 ± 2 °C for 8 h) and stored (refrigerated, ambient and accelerated condition) samples of four cultivars (Krishna, Kanchan, NA-7 and Chakaiya). Salt pretreated dried samples showed better retention of nutrients and colour as compared to untreated. Retention of ascorbic acid, total phenolic content and antioxidant activity (IC₅₀ value) in pretreated dried samples were in the range of 79.51-84.89%, 176.5-220.3 mg GAE/g db and 9.48 to 17.74 mg/µl, respectively. Colour retention was also found to be better in salt pretreated samples. Ambient storage condition resulted in higher retention of ascorbic acid and colour compared to accelerated condition. Taking into consideration, the nutritional value of the fresh Amla, ability to retain nutritional value and color during drying and storage, NA-7 cultivar Amla (pretreated with 1% salt, tray dried at 55 °C for 8 h) is the most suitable for preparation of Amla powder. The method developed in the present work is devoid of blanching step and found to be effective in retaining the nutrients during drying and storage and can be employed also for drying of similar fruits and vegetables.

Analysis of microplastics in wetland samples from coastal Ghana using the Rose Bengal stain

The use of optical microscope remains the most commonly used technique for microplastic identification and quantification despite major limitations with misidentifications and biases. We evaluated the use of the 1% Rose Bengal stain in improving the identification of microplastics after a standard microplastic isolation process. The stain discriminated organic materials from potential microplastics with significant differences between numbers observed before (6.65 ± 5.73) and after staining (2.91 ± 3.43). Numbers of potential microplastics observed under the conventional method (without staining) in sediment, feacal matter of shorebirds and the lagoon water were respectively 3.55 g^-1, 0.8 g^-1 and 0.13 ml^-1 but reduced to 1.85 g^-1 of sediment, 0.35 g^-1 of feacal material and 0.09 ml^-1 of water after staining. Colour composition of potential microplastics under the conventional method was brown (31.0%), black (26.5%), white (20.2%), translucent (16.7%) and red (5.6%). After staining, brown (49,2%), black (30.5%) white (2.3%) and translucent (18.0%) were retained but distinction could not be made between stained organic items and red-coloured microplastics. It was clear that the stain has the potential in improving microplastic identification but requires further investigations.

Surprising absence of association between flower surface microstructure and pollination system

The epidermal cells of flowers come in different shapes and have different functions, but how they evolved remains largely unknown. Floral micro-texture can provide tactile cues to insects, and increases in surface roughness by means of conical (papillose) epidermal cells may facilitate flower handling by landing insect pollinators. Whether flower microstructure correlates with pollination system remains unknown. Here, we investigate the floral epidermal microstructure in 29 (congeneric) species pairs with contrasting pollination system. We test whether flowers pollinated by bees and/or flies feature more structured, rougher surfaces than flowers pollinated by non-landing moths or birds and flowers that self-pollinate. In contrast with earlier studies, we find no correlation between epidermal microstructure and pollination system. The shape, cell height and roughness of floral epidermal cells varies among species, but is not correlated with pollinators at large. Intriguingly, however, we find that the upper (adaxial) flower surface that surrounds the reproductive organs and often constitutes the floral display is markedly more structured than the lower (abaxial) surface. We thus conclude that conical epidermal cells probably play a role in plant reproduction other than providing grip or tactile cues, such as increasing hydrophobicity or enhancing the visual signal.

Suitability of alternative wood types other than American oak wood for the ageing of Sherry vinegar

The present study has consisted on the monitoring of Sherry vinegar during a whole year ageing in American oak, French oak, Spanish oak and chestnut barrels in order to determine the suitability of alternative wood types other than American oak for the ageing of this type of vinegar. Thirty-two volatile compounds were quantified, CIELab parameters were determined and sensory analyses were carried out during the whole process. The multivariate analysis of the data revealed that the samples that had been aged in Spanish oak barrels were getting more similar to those aged in French oak as the ageing process was progressing. Furthermore, the samples that had been aged in chestnut presented some volatile compounds significantly different from American oak. Finally, although French oak wood transferred the best organoleptic characteristics to Sherry vinegar, Spanish oak and chestnut seemed to be satisfactory alternatives for the ageing process.

Reduction of nitrate and nitrite in Iberian dry cured loins and its effects during drying process

Four batches of Iberian dry-cured loins were manufactured with reduced ingoing amounts of both nitrate and nitrite: 150 mg/kg, 75 mg/kg, 37.5 mg/kg and 0 mg/kg. The effect of reducing or removing nitrate and nitrite and time of drying on physicochemical parameters (moisture, pH, water activity, chloride and residual nitrate and nitrite contents), instrumental colour and nitrosylmyoglobin content, lipid and protein oxidation and on microbiological counts (L. monocytogenes, aerobic mesophilic bacteria and moulds and yeast counts) were investigated. Lipid oxidation increased during the drying process being higher for non-added NO₃^-/NO₂^-, meanwhile protein oxidation affected also those with 37.5 and 75 mg/kg of NO₃^-/NO₂^- added. The removal of these additives affected instrumental colour coordinates and total colour changes showing that the variation of coloration would be perceptible by the consumer. Nitrosylmyoglobin content was significantly higher for NO₃^-/NO₂^- added loins. Reduced levels of these additives up to 37.5 mg/kg did not show significant effects on their physico-chemical, microbiological and colour.

Meat quality in the Danish pig population anno 2018

The level of meat quality was assessed in a random sample of the Danish pig population. No PSE was found in m. semimembranosus, and, depending on the definition of PSE, no pigs or only 2% of the pigs were categorised as having PSE in the M. longissimus lumborum. The ultimate pH had a low variability in M. longissimus lumborum (2.5%), m. semimembranosus (2.7%) and m. semispinalis capitis (4.9%) indicating that the quality of the meat with respect to these attributes was uniform. The drip loss was as high as 7%, although on average (2.23%) its value was lower than that previously found in a sample of the Danish pig population. A gender difference between entire male pigs and castrates was seen for drip loss and tenderness (shear force), with loins from castrates being less exudative (P < .001) and more tender (P < .01) than those from entire males. In conclusion, the Danish pig population showed a uniform meat quality.

The BELT and phenoSEED platforms: shape and colour phenotyping of seed samples

BACKGROUND

Quantitative and qualitative assessment of visual and morphological traits of seed is slow and imprecise with potential for bias to be introduced when gathered with handheld tools. Colour, size and shape traits can be acquired from properly calibrated seed images. New automated tools were requested to improve data acquisition efficacy with an emphasis on developing research workflows.

RESULTS

A portable imaging system (BELT) supported by image acquisition and analysis software (phenoSEED) was created for small-seed optical analysis. Lentil (Lens culinaris L.) phenotyping was used as the primary test case. Seeds were loaded into the system and all seeds in a sample were automatically individually imaged to acquire top and side views as they passed through an imaging chamber. A Python analysis script applied a colour calibration and extracted quantifiable traits of seed colour, size and shape. Extraction of lentil seed coat patterning was implemented to further describe the seed coat. The use of this device was forecasted to eliminate operator biases, increase the rate of acquisition of traits, and capture qualitative information about traits that have been historically analyzed by eye.

CONCLUSIONS

Increased precision and higher rates of data acquisition compared to traditional techniques will help to extract larger datasets and explore more research questions. The system presented is available as an open-source project for academic and non-commercial use.

Association between coat colour and the behaviour of Australian Labrador retrievers

Background

Making assumptions regarding temperament and intelligence based on the physical appearance of dogs can be a conscious or unconscious human act. Labrador retrievers with chocolate-coloured coats are anecdotally considered to be less trainable and more hyperactive and aggressive than their black or yellow peers. To test these assertions, we analysed the owner-reported behavioural traits of Labradors in relation to both their observable coat colour, and their TYRP1 and MC1R genotypes.

Results

We used the results of an owner-based questionnaire to determine scores for 21 behavioural traits and test whether these scores varied with coat colour (n = 225). Familiar dog aggression was the only trait that was found to vary significantly with coat colour (P = 0.013). Yellow Labradors had a higher score than chocolate Labradors, even when corrected for multiple testing (P = 0.021).

We repeated the analyses for a subset of 63 Labradors with available genotyping data for the genes (MC1R and TYRP1) that are known to determine the primary coat colours in Labradors. Familiar dog aggression scores varied with both the observed coat colour and MC1R genotype. Dogs homozygous for MC1R recessive allele (with yellow coat colour) scored higher for familiar dog aggression than either black or chocolate Labradors. However, no association maintained significance when incorporating Bonferroni correction. Dog trainability scores decreased additively as the number of recessive brown alleles for TYRP1 increased. This allelic association was independent of the observable coat colour. Dogs homozygous for the brown allele were considered less trainable than dogs with no brown alleles (P = 0.030).

Conclusions

Our results do not support that chocolate-coloured Labradors are more hyperactive or aggressive than either black or yellow Labradors. Trainability scores varied with TYRP1 genotype but not the observable coat colour. Further validation is required.

Effect of heat processing on the nutrient composition, colour, and volatile odour compounds of the long-horned grasshopper Ruspolia differens serville

Heat processing is commonly used to prepare edible insects for consumption. This study aimed at determining the effect of boiling and subsequent oven roasting on Ruspolia differens' nutrient composition, colour and odor compounds. Boiling leads to: a significant increase in protein and decrease in fat content on a dry matter basis; a minimal influence on its amino and fatty acids profile; a significant reduction in its ash content due to leaching of phosphorus, potassium and sodium; a significant increase in iron, zinc, copper, manganese and calcium content; and a fivefold reduction in the amount of vitamin B12. Roasting leads to a relative increase in the amount of calcium and trace mineral elements but doesn't affect other nutrients. Roasting results into a more uniform colour intensity when green and brown polymorphs are roasted together. Lipid oxidation is responsible for the colour and aroma of heat processed R. differens.

Long-term versus short-term consistency in the grapheme-colour synaesthesia: Grapheme-colour pairings can change in adulthood

The aim of the article is to examine the stability of grapheme-colour matchings in adulthood. We carried out a panel study using computerized tests to measure short-term and long-term consistency. We conducted three testing rounds during 1 year and a half with a resulting sample of 26 synaesthetes. Our results suggest that the colours associated with individual graphemes can change substantially (e.g. from "salmon" to "aquamarine") even during this relatively short time period. Based on a linear mixed model, we further argue that short-term and long-term consistency should be distinguished because these scores tend to differ. These results thus complement previous findings on the issue of grapheme-colour consistency and have important consequences for the study of synaesthesia in the future.

The visual appearance of beer: A review concerning visually-determined expectations and their consequences for perception

This review critically evaluates the literature concerning the impact of visual appearance cues (including colour, foam, and cloudiness) on people's perception in the beer category. The authors assess both the sensory expectations that are elicited by the visual appearance of beer, and the extent to which those expectations carry-over to influence the actual tasting experience. Beer is a particularly intriguing category to study since the differing production rules in different countries mean that there is not always the same scope to modify the colour in order to meet perceived consumer demands. What is more, there is currently disagreement in the literature concerning the impact of beer colour and foam on people's expectations of beer prior to tasting, and their multisensory flavour perception on tasting. Given how much beer is consumed annually, it is surprising that more research has not been published that assesses the undoubtedly important role of visual appearance in this beverage category. Part of the reason for this may simply be that it is difficult to create consistent experimental stimuli given the rapid transition of the head of the beer post-serving.

Object colours, material properties and animal signals

Humans and other animals often use colour to recognise objects regardless of their context - as a measure of material properties rather than of their contrast with a background. Most work on visual communication signals is, however, concerned with colour differences, typically scaled by just noticeable differences (JNDs). Here, we move from the prevailing physiological framework to understand what a given colour or type of colour might tell an animal about an object. To this end, we consider the properties of object colour solids, which represent the colour gamut of reflective materials for a given type of animal eye. The geometry of colour solids reveals general relationships between colours and object properties, which can explain why certain colours are significant to animals, and hence evolve as signals. We define a measure of colour vividness, such that points on the surface are maximally vivid and the 'grey' centre is minimally vivid. We show that a vivid colour for one animal is likely to be vivid for others, and highly vivid colours are less easily mimicked than less vivid colours. Furthermore, vivid colours such as black, white, red and blue, as well as pale colours and certain unsaturated shades, are produced by pure or orderly materials. Such materials are created and maintained against entropic processes. Vivid colours are therefore indicative of ecological affordance or biological function, so it is valuable to have low-level psychological biases towards these colours regardless of any specific significance they might have to the receiver.

Sucrose enhances colour formation in dry sausages by up-regulating gene expression of nitric oxide synthase in Staphylococcus vitulinus

The effects of glucose and sucrose on the gene expression of nitric oxide synthase (NOS) in Staphylococcus vitulinus and colour formation in dry sausages were investigated. The results showed that sucrose addition promoted nitric oxide (NO) production in media when compared with glucose. In addition, sucrose could up-regulate nos (encoding NOS) and katA (encoding catalase KatA) gene expression by enhancing oxidative stress levels. In the sausages inoculated with S. vitulinus, a*-values (indicating redness) of the sausages with added sucrose were higher than those of samples with added glucose (P < 0.05) but did not differ from those in the nitrite treatment group (P > 0.05). The UV-vis spectra results showed that nitrosylmyoglobin (NO-Mb) was formed in the sausages with either S. vitulinus or nitrite added. In the S. vitulinus-inoculated sausages, sucrose addition led to a higher NO-Mb content than that after glucose addition, which was attributed to up-regulation of the nos gene. This study provides a potential method to enhance NO yield in S. vitulinus and colour formation in dry sausages without nitrite addition.

The attentional guidance of individual colours in increasingly complex displays

The use of colours is a prevalent and effective tool for improving design. Understanding the effect of colours on attention is crucial for designers that wish to understand how their interfaces will be used. Previous research has consistently shown that attention is biased towards colour. However, despite previous evidence indicating that colours should be treated individually, it has thus far not been investigated whether this difference is reflected in individual effects on attention. To address this, a visual search experiment was conducted that tested the attentional guidance of six individual colours (red,blue, green, yellow, orange, purple) in increasingly complex displays. Results showed that the individual colours differed significantly in their level of guidance of attention, and that these differences increased as the visual complexity of the display increased. Implications for visual design and future research on applying colour in visual attention research and design are discussed.

Drinking through rosé-coloured glasses: Influence of wine colour on the perception of aroma and flavour in wine experts and novices

Wine colour carries a myriad of meanings regarding the provenance and expected sensory qualities of a wine. That meaning is presumably learnt through association, and part of a wine taster's skill comes from being able to decode information that can be discerned in subtle variations in the colour of the wine that they drink/evaluate. However, reliance on colour means that wine tasters, especially experts, often exhibit colour-induced olfactory biases. The present study assesses how wine colour - specifically the pink hue of rosé wines - can influence both the perceived aroma and flavour in a large sample of wine novices and experts. Participants (N = 168) tasted three wines - a white wine (W), a rosé wine (R), and the white wine dyed to match the rosé (Ŕ) - and freely selected three aroma and three flavour descriptors from a list. They also rated wine liking, flavour intensity, and description difficulty for each wine. Linguistic analysis demonstrated that those with wine tasting experience judged Ŕ to be much more similar to R than to W, even though Ŕ and W were the same. Moreover, red fruit descriptors were attributed to both R and Ŕ, especially in terms of flavour. Quantitative ratings revealed that Ŕ was liked less than W or R, and participants found it more difficult to describe Ŕ than R. These results demonstrate that while participants found the dyed rosé somehow different from the undyed wines, they nevertheless used the red fruit terms to describe its aroma and flavour. The implications of such results in terms of cognitive representations of wine and the role of sensory expectations are discussed.

The influence of spray drying parameters and carrier material on the physico-chemical properties and quality of chokeberry juice powder

Chokeberry juice is used in the food industry because of its antioxidant activity as well as anti-diabetes, anti-mutagenic, bacteriostatic, anti-inflammatory and anti-virus properties. However in a liquid form its active ingredients can be unstable, so conversion into powder form is required. To improve the quality of the final product and extend information about the properties of chokeberry powder the aim of the study was to examine the relationship of inlet air temperature (160 °C, 200 °C) and carrier type maltodextrin (MD) 10DE and 15.6DE, arabic gum (AG) and their mixtures (AG:MD10 and AG:MD15—1:1, 1:3, 3:1) with the amounts of anthocyanins and polyphenols and selected physical properties of powders obtained after spray drying. Moreover stability of anthocyanin was tested after storage Obtained powders were characterized by low water activity (< 0.26), high dry matter content (97–99%) and good hygroscopic properties. Saccharification level of maltodextrin had no impact on the amount of bioactive components enclosed inside the capsules. Moreover, the mixtures of carriers, AG:MD appeared to have a large potential to ensure a high quality of chokeberry powder with high content of anthocyanin (1694–2028 mg/100 g) and polyphenols (about 3000 mg/100 g d.m.). Storage temperature mostly has no statistically significant influence on content of active ingredients, but an increase in colour coefficents was observed. The contents of anthocyanins and polyphenols were higher in powders stored at 4 °C than at 25 °C.

The application of unconventional technologies as pulsed electric field, ultrasound and microwave-vacuum drying in the production of dried cranberry snacks

A lot of effort is put to decrease the energy consumption of drying. This effect might be achieved by shift of a drying technology e.g. from a hot-air to a microwave-vacuum method. Moreover, an unconventional pre-treatment such as ultrasound or pulsed electric field may modify a cellular tissue, what influences drying kinetics of plant tissue. The aim of the study was to analyse the quality of microwave-vacuum dried, osmodehydrated (OD) cranberries processed by the means of blanching and ultrasound (US) or blanching followed by pulsed electric field and sonication (PEF + US) in comparison to traditionally treated material. Physical, chemical and sensorial properties of cranberry fruits were assessed. What is more, the impact of aforementioned unconventional treatments on the kinetics of microwave-vacuum dried cranberries was studied. Microwave-vacuum drying process was very short (25-38 min) in comparison to convective drying, which lasted several hours (13.2 h). Most of the samples subjected to US and PEF + US treatments before OD and drying were characterized by similar or a higher amount of bioactive compounds such as polyphenols, anthocyanins and flavonoids, and better colour and taste, as compared to cut osmodehydrated cranberry fruits subjected to convective drying (reference samples).

Application of infrared-assisted steam blanching to improve enzymatic inactivation and quality retention of Chrysanthemum indicum L. flower

The effects of innovative infrared-steam blanching (ISB) on the peroxidase (POD) inactivation, POD inactivation kinetics, characteristic component (phenolics, carotenoids and flavonoids) content, colour and regeneration of POD activity during storage of Chrysanthemum indicum L. flowers were comparatively studied following steam blanching (SB) and infrared blanching (IB). ISB and SB allowed a stable surface temperature of the flowers at approximately 100 °C, and IB caused the temperature rose up to a high value of 129.2 °C. POD was inactivated to 5.7% of its residual activity after ISB for 90 s, 5.8% after SB for 180 s and 5.3% after IB for 270 s. In all processes, the POD inactivation kinetics followed a first-order model (R ² varied from 0.932 to 0.957) and ISB achieved lower T _1/2, E _a and D values and a higher k value than SB and IB. The sample blanched with ISB maintained more characteristic components and colour retention than those blanched with SB and IB. Moreover, ISB allowed the brightest colour and prevented the regeneration of POD activity in dried C. indicum flowers during storage. Therefore, ISB for 90 s at 100 °C is recommended as a more suitable method for blanching C. indicum flowers. The findings in the current work provide a new blanching method for natural plant products.