Higher Hue Angle Research Articles

Chitosan/zein-based sustained-release composite films: Fabrication, physicochemical properties and release kinetics of tea polyphenols from polymer matrix

This study investigated the properties of chitosan/zein/tea polyphenols (C/Z/T) films and analyzed the release kinetics of tea polyphenols (TP) in various food simulants to enhance the sustainability and functionality of food packaging. The results revealed that TP addition enhanced the hydrophilicity, opacity and mechanical properties of film, and improved the compatibility between film matrix. 1.5 % TP film showed the lowest lightness (76.4) and the highest chroma (29.1), while 2 % TP film had the highest hue angle (1.5). However, the excessive TP (above 1 % concentration) led to a decrease in compatibility and mechanical properties of film. The TP concentration (2 %) resulted in the highest swelling degree in aqueous (750.6 %), alcoholic (451.1 %), and fatty (6.4 %) food simulants. The cumulative release of TP decreased to 16.32 %, 47.13 %, and 5.87 % with the increase of TP load in the aqueous, alcoholic, and fatty food simulants, respectively. The Peleg model best described TP release kinetics. The 2 % TP-loaded film showed the highest DPPH (97.13 %) and ABTS (97.86 %) free radical scavenging activity. The results showed TP release influenced by many factors and obeyed Fick's law of diffusion. This study offered valuable insights and theoretical support for the practical application of active films.

Production of a mixed fruit juice powder using mixture analysis and a fuzzy model

The present work aimed to find a mixed fruit juice powder with high antioxidant activity and sensory score. A two-step fuzzy algorithm and fuzzy toolbox were applied to produce acceptable sensory data for the mixture analysis design. The mixture design was then analysed using two responses of sensory and antioxidant activity, and the optimised beverage consisted of red grape (20.4%), mulberry (75.6%), and strawberry (4.0%). As compared to single fruit juices, the selected mixture yielded high content of phenolic compounds with desirable antioxidant activity and sensory score. Spray- and freeze-drying were then compared for the fruit juice powder production from selected mixed juices formulated with 20% maltodextrin (DE = 20). A significant (p < 0.05) difference was observed between the powder yield (82.0% in comparison to 51.7%), free radical scavenging activity (85.6% in comparison to 75.4%), and total phenolic content (2958.8 in comparison to 2791.4 mg GAE/L) of the freeze- and spray-dryer, respectively. Furthermore, the spray-dried powder was much lighter than the freeze-dried powder, with a lower chroma index, redness, and higher hue angle. Overall, freeze-drying was less destructive than spray-drying in the powder production from the mixed juice.

Changes in Pomological and Physical Parameters in Rosehips during Ripening

Rosehips of various Rosa spp. are well known for having human health-promoting compounds like mineral nutrients, vitamins, fatty acids, and phenolic compounds. However, little is known about rosehip characteristics which describe the fruit quality and may indicate appropriate harvest times. Our study evaluated the pomological (width, length, and weight of fruits, flesh weight, and seed weight), texture, and CIE colour parameters (L*, a*, and b*), chroma (C), and hue angle (h°) of rosehip fruits of Rosa canina, Rosa rugosa, and genotypes of Rosa rugosa 'Rubra' and 'Alba', harvested at five ripening stages (I-V). The main results revealed that genotype and ripening stage significantly affected parameters. The significantly longest (R. canina) and widest fruits (R. Rugosa) were measured at ripening stage V. Genotypes of R. rugosa 'Rubra' and 'Alba' had significantly higher fruit and flesh weights at ripening stage V. Rosehips of all investigated genotypes expressed darkness (lower L*) during ripening, and had the highest hue angle h° values at ripening stage I while the lowest was at stage V. The significantly lowest skin elasticity of rosehips was found at stage V. However, R. canina was distinguished by the highest fruit skin elasticity and strength. As our results show, the desired pomological, colour, and texture features of various species and cultivars rosehips can be optimised according to the harvest time.

Effect of honey and lemon juice on the physicochemical, nutritional, microbial and antioxidant properties of guava–pineapple jelly during storage periods

Jellies are usually preserved by artificial preservatives where they have harmful side effects and health hazards especially to infants. Honey and fresh lemon extract juice is a natural preservative and is considered a good substitute for artificial preservative. Due to increasing level of demand regarding health concern issue safe food, an attempt has undertaken to formulate the artificial preservative free guava–pineapple jelly and their marketability, physicochemical, bioactive compounds, microbial and antioxidant properties analysis during storage. In this study, the jelly was formulated using artificial preservative potassium metabisulphite (KMS) (T1), natural preservative honey and fresh lemon extract juice (T2 and T3), without artificial and natural preservative (T4) using different proportion of guava–pineapple extracted juice. Results of different treated jelly showed that T2 and T3 jelly was nutritionally superior. Bioactive compounds and antioxidant properties was highly present in T2 and T3 jelly. The brightest color (L* and C*) and highest hue angle (H*) value was noted in honey and fresh lemon extract juice treated jelly T2 and T3 upto 8 months of storage but after 9 months, darkest color was noted gradually. The consumer acceptance was extended to honey and lemon extract juice treated jelly (T2 and T3) for their impressive color and flavor. High incidence of microbial load was recorded in preservative free (both natural and artificial) jelly (T4). Low incidence of microbial load obtained from this study gives an indication that T2 and T3 jelly is microbiologically safe as natural jelly. Shelf life of natural preservative treated jelly (T2 and T3) could be extended upto 8 months and artificial preservative treated jelly could be upto 9 months (T1) at ambient condition without any quality deterioration. Overall, honey and fresh lemon extract juice are valuable source of natural preservative for formulation of fruit jelly. The processors could process and preserve the fruit jelly with decent aroma by applying this technology as an alternative to artificial food additives.

Effect of Variety and Sex on the Carcass and Meat Quality Traits of Guinea Fowl (Numida meleagris L.).

The aim of this study was to evaluate selected parameters of carcass and meat quality in 16-week-old pearl gray and lavender guinea fowl. The birds were raised in summer and fall, in an extensive system. Until 4 weeks of age, the birds were kept indoors, and from week 5 until slaughter they could use outdoor space enclosed by a fence, adjacent to the building. Guinea fowl were fed complete chicken diets: starter (weeks 0-6), grower (weeks 7-12), and finisher (weeks >13). In comparison with lavender guinea fowl, pearl gray birds had higher live weight at slaughter (p = 0.001) and higher carcass weight (p = 0.001). Females, compared with males, had a higher carcass dressing percentage (p ˂ 0.001), lower liver weight (p = 0.008), lower heart weight (p ˂ 0.001), and lower total weight of giblets (p = 0.004). The leg muscles of pearl gray guinea fowl, compared with those of lavender birds, had a higher content of dry matter (p ≤ 0.029). The breast muscles (p ˂ 0.001) and leg muscles (p = 0.017) of lavender guinea fowl contained less fat than the muscles of pearl gray birds. The breast muscles of females had a higher content of dry matter (p = 0.044) and ash (p = 0.016), and lower total collagen content (p = 0.028) than the breast muscles of males. The leg muscles of females were characterized by a higher pH (p ˂ 0.001), and lower cooking loss (p = 0.004) and drip loss (p = 0.005) than the breast muscles of males. The breast muscles of lavender guinea fowl, compared with those of pearl gray birds, were characterized by a higher chroma value (p ˂ 0.001), and a higher contribution of redness (p ˂ 0.001) and yellowness (p = 0.002), and their leg muscles were lighter in color (p ˂ 0.001), with a higher contribution of yellowness (p = 0.041) and a higher hue angle (p = 0.037). The value of chroma (p = 0.004) and the contribution of yellowness (p = 0.002) were higher in the breast muscles of females, compared with males. Neither variety nor sex affected (p > 0.05) the evaluated sensory properties of guinea fowl meat or the proportions of total SFAs, total UFAs, total MUFAs, and total PUFAs in the intramuscular fat (IMF) of breast and leg muscles. Meat from guinea fowl of both analyzed varieties can be an excellent alternative to more popular types of poultry meat due to its high nutritional value and eating quality.

Spraying of calcium carbonate nanoparticles on pineapple fruit reduces sunburn damage

This study aimed to evaluate the effect of different concentrations of calcium carbonate nanoparticles preharvest sprayed on pineapple fruit. The treatments consisted of five concentrations of calcium carbonate nanoparticles: 0, 12.5, 25, 50, 100, and 200 g ha−1. The quality parameters were analyzed: soluble solids content (SSC), titratable acidity (TA), ratio (SSC/TA), ascorbic acid content, and firmness; also, colorimetric parameters on fruit pulp and peel: lightness (L*), coordinates a* and b*, chroma, hue angle, and yellowing index. The spraying of calcium carbonate nanoparticles reduced the damage caused by sunburn, increasing fruit quality. This effect was evidenced in fruit color by the increased L*, higher Hue angles, and lower yellowing index in the peel and pulp. In addition, we observed increased firmness, SSC/TA, and ascorbic acid in the pulp. Thus, it maintained quality characteristics and fruit color. This study proposes two calcium carbonate nanoparticles spraying during pineapple cultivation to control fruit sunburn, especially in tropical regions, guaranteeing high-quality fruit production and extending its postharvest commercialization.

γ-Aminobutyric acid treatment reduces chilling injury and improves quality maintenance of cold-stored Chinese olive fruit

This study developed a useful technique to maintain quality and mitigate chilling injury of cold-stored Chinese olive fruit. Influence of dose (0, 0.5, 1.0, 1.5, 2.0 mM) of γ-aminobutyric acid (GABA) on the quality attributes and chilling damage of Chinese olive when stored at 2 °C for 100 d was investigated. Compared to control samples, GABA-treated fruit displayed lower chilling injury index, cell membrane permeability, and weight loss percentage, but higher hue angle h° value, higher levels of chlorophyll, total soluble sugar, sucrose, total soluble solids, titratable acid, and tannin, and 1.0 mM GABA is the optimal concentration to retain the quality attributes and reduce the chilling injury of Chinese olive fruit during cold storage.

Effects of modified atmosphere packaging on physicochemical properties of fresh‐cut ‘Deveci’ pears

This study aimed at determining the respiration rate of fresh-cut ‘Deveci’ pears and studying the effects of modified atmosphere packaging (MAP) on its quality. Respiration rate decreased with decreasing O2 level and it was determined as 1.04 ml O2/kg/hr or 1.16 ml CO2/kg/hr, under 4% O2+5% CO2 gaseous environment at 4°C. Michaelis-Menten with no inhibition was the best model to fit the respiration data. MAP under 2.15% O2+8.70% CO2 equilibrium atmosphere resulted in a lower total color change, a*-value, chroma, and a higher hue angle and L*-value compared to the air-control during 8-day storage at 4°C. The firmness of pear slices was better maintained in the MAP. The MAP treatment was successful in controlling the total soluble solids, pH, and titratable acidity of the fresh-cut pears. As a result, MAP of fresh-cut ‘Deveci’ pears has an important potential to preserve the physicochemical properties of the product. Novelty impact statement Respiration rate of fresh-cut ‘Deveci’ pears was reduced by 3–4-fold to 1.04 ml O2/kg/hr or 1.16 ml CO2/kg/hr values by modified atmosphere of 4% O2 and 5% CO2 at 4°C. Michaelis-Menten model with no CO2 inhibition was the best model for respiration rate as a function of O2 and CO2 concentrations. Modified atmosphere packaging improved texture and color, and maintained acidity and total soluble solids of fresh-cut ‘Deveci’ pears during storage.

Salicylic and Methyl Salicylic Acid Affect Quality and Phenolic Profile of Apple Fruits Three Weeks before the Harvest.

Effects of spraying over apple trees (Malus domestica; ‘Topaz’) with methyl salicylic acid (MeSA) and SA during fruit maturation were investigated for quality parameters (weight, firmness, hue angle, red blush, yield) and phenolic profile of the peel and pulp (HPLC–mass spectrometry). These treatment effects were also investigated for activities of the phenylpropanoid pathway enzymes phenylalanine ammonia-lyase, chalcone synthase and isomerase (combined), and flavanone-3β-hydroxylase. The MeSA and SA treatments resulted in poor fruit peel coloration, with higher hue angles and 20% and 10% lower red blush, respectively. Anthocyanin levels were also significantly lower (56%) for MeSA treatment. MeSA stimulated activities of phenylalanine ammonia-lyase and chalcone synthase/isomerase, which resulted in higher levels of flavanols (to 34%), flavonols (to 33%), and hydroxycinnamic acids (to 29%), versus control. Therefore, while these salicylate treatments improve levels of some beneficial polyphenols, they also have negative effects on the external quality characteristics of the fruit.

Alginate-based microparticles structured with different biopolymers and enriched with a phenolic-rich olive leaves extract: A physico-chemical characterization

Encapsulation of olive leaves extracts (OLE), rich of healthy components like Oleuropein, Hydroxytyrosol and Verbascoside, represents a new challenge to improve stability and nutritional value of food as well as a way to recover value added compounds from by-products, contributing to a more sustainable food system. In this context, OLE-loaded microbeads of Na alginate alone or in combination with Pectin, Na Caseinate or Whey protein isolates, were produced by emulsification internal ionotropic gelation. Encapsulation efficiency of the main phenolic compounds (Oleuropein, Hydroxytyrosol, Verbascoside) was carried out along with microparticles morphological characterization by scanning electron microscopy (SEM), thermal properties by differential scanning calorimetry (DSC) and color. Encapsulation efficiency resulted higher for Alginate/Pectin, whilst Alginate/Caseinate was the less performing system, probably due to the lower interaction with polyphenols. SEM revealed collapsed structures and continuous smooth surfaces for Alginate and Alginate/Pectin microbeads while more regular structures and porous surfaces were observed for Alginate/Caseinate and Alginate/Whey proteins. Higher hue angle and lower chroma values were observed for all the beads with respect to the pure extract, indicating a reduction of the yellow/brown color. DSC highlighted higher thermal stability for the microbeads in comparison to the original ingredients, showing also new thermal transitions related to bonds formation between polymers and OLE.

Effect of High CO2 Treatment and MA Packaging on Sensory Quality and Physiological-Biochemical Characteristics of Green Asparagus (Asparagus officinalis L.) during Postharvest Storage

Green asparagus is vulnerable to thrips that carry microorganisms and cause deterioration in quality. The effects of 60% CO2 treatment, which is used to kill thrips, combined with perforated (P) or modified atmosphere (MA) packages during cold storage, on the sensory quality and physiological–biochemical characteristics of asparagus were investigated. MA packaging yielded an asparagus shelf-life five days longer than P packaging. The 60% CO2 treatment for 48 h at 4 °C packaged with MA film (CO2-48 h-4 °C-MA) showed a lower number of aerobic bacteria, yeast, and mold. Yellowing of asparagus was retarded, as shown by higher hue angle and chlorophyll content and lower chlorophyllase activity. Also, CO2-48 h-4 °C-MA treatment inhibited the reduction of soluble solids content in asparagus. Likewise, all high CO2 treatments showed lower electrolyte leakage (EL), with CO2-48 h-4 °C-MA demonstrating the minimum EL. The effectiveness of high CO2 on maintaining sensory qualities was observed, with a score higher than 3.0. In conclusion, CO2-48 h-4 °C-MA treatment during cold storage was effective for maintaining post-harvest sensory qualities and physiological–biological traits of asparagus, and provided strong inhibition of microflora growth during the storage period.

Effect of foaming agents on process conditions, characteristics, and stability of foam‐mat freeze‐dried pandan (Pandanus amaryllifolius) powder

Foam-mat freeze-drying (F-FD) of aqueous pandan extract with various foaming agents (egg white protein, sodium caseinate, and METHOCEL) was carried out to improve the process conditions, physicochemical properties, and stability of pandan powder. The foamed pandan solution with egg white protein (F-EW) provided the most stable foam structure and shortened drying time to 6 hr, while the control took 24 hr to dry at the same sample thickness. The F-EW freeze-dried pandan powder (FDPP) had the highest hue angle, the highest greenness (a* value), the lowest bulk density, and high solubility. The reaction rate constants for the physicochemical changes in foamed-freeze-dried pandan powders were lower than those of the control and the highest color stability was recorded for F-EW FDPP when stored at high temperature (37°C) for 12 weeks. Egg white at a concentration of 10% w/w is an appropriate foaming agent for producing pandan powder via the F-FD. Practical applications Natural pandan leaf extract is a commercially available product nowadays both in concentrate and powder form. Functional ingredients are offered to the health-conscious consumers, such as natural pandan powder with prebiotic. Foam-mat freeze-dried pandan powder with various types of foaming agents, such as egg white protein, sodium caseinate, and METHOCEL may be the new alternative technology for the production of functional ingredients which not only use as a natural food colorant and flavor but also as the foaming aid agent in foam-type food products.

Evaluation of Different Conventional Breading Materials on Functional Quality Attributes of Battered and Breaded Fish Cutlets

ABSTRACT Breading and battering of fish results in a physically superior product with a higher economic value from low-value fish. The present work was undertaken to evaluate three conventional breading materials for fish cutlets. Standard sized fish cutlets were molded with and dipped in a batter mix, followed by breading with bread crumbs (CB), pressed rice (PR), or noodle vermicelli (NS). The products were evaluated for coating parameters such as pickup, adhesion degree, cooking loss, and frying yield. The coating pickup ranged from 10.95% to 36.00%, and a maximum pickup was found with pressed rice (PR). Similarly, the adhesion degree in PR was 26.47%, which was highest among the three. Cooking loss was highest with control (conventional breadcrumb) at 15.92%. After analyzing the frying yield, it was found that PR yielded the maximum at 16.75% and less oil absorption. PR also had significantly (p < .05) higher hue angle value than both the NS and CB. Maximum browning and tough texture was observed in the NS sample. Frying tolerance was better with PR breading, which maintained better color during deep frying operations. This study can help industries to utilze low-cost breading material in preparing enrobed snack products.

Effects of Visual Cues on Consumer Expectation, Emotion and Wellness Responses, and Purchase Intent of Red Chili Powders.

The effects of visual cues on familiarity, expected heat intensity, liking of appearance, emotional and wellness responses, and purchase intent (PI) before and after disclosing information associated with red chili powders were determined using a 3-point scale, a 15-cm line scale, a 9-point hedonic scale, a 15-cm line scale, and a binomial scale, respectively. In this study, consumers only visually evaluated red chili powder samples without sniffing nor tasting. Eight chili powders were prepared according to a 23 factorial design: roasted (Ro) compared with unroasted (Un); whole pod with seeds (Wh) compared with seedless (Sl); coarsely (Cr) compared with finely ground (Gr). Thai consumers (N = 230) were generally more familiar with samples having coarse particles and more reddish color (lower hue angle and higher a* values) than samples having finely ground particles and less reddish/more yellowish color (higher hue angle and lower a* values). The expected heat intensity and liking scores for appearance were lower for samples with higher hue values, particularly RoWhGr and RoSIGr samples. All scores for emotion/wellness terms, except curious, were generally higher for samples with lower hue angle and higher a* values (redness). The consumer familiarity to the appearance of the samples influenced expected heat intensity, liking of appearance, and emotion/wellness responses. PI increased by >10% after presenting "organic," "aflatoxin free," and "organic and aflatoxin free" product statements to consumers. Results showed that familiarity, overall liking of appearance, color liking, fine particles liking, and healthy as well as wild terms were significant predictors for PI (odds ratio = 1.282, 1.519, 1.314, 1.158, 1.056, and 0.939, respectively) of red chili powders. PRACTICAL APPLICATION: This study showed that consumer familiarity to the appearance (visual cues) of red chili powder affected expected heat intensity, liking of appearance, and emotion/wellness responses, which, in turn, affected purchase intent (PI). Samples with more reddish color and coarse particles were perceived to be more familiar than those with more yellowish color and finer particles. Familiarity, overall liking of appearance, color liking, fine particles liking, and healthy and wild terms were significant predictors for PI of chili power. The results demonstrated the importance of visual cues on the consumers' expectation and PI of red chili powder, thus offering valuable information for manufacturers.

Effects of Aloe vera gel and MAP on bioactive compounds and quality attributes of cherry laurel fruit during cold storage

This study was conducted to determine the effects of Aloe vera (AV) and modified atmosphere packaging (MAP) on physiological and chemical quality attributes of cherry laurel (Prunus laurocerasus L.) fruit during the cold storage at 0 ± 0.5 °C and 90 ± 5% RH. Throughout the storage, fruit weight and firmness losses were delayed with AV and MAP treatments. At the end of storage, the respiration rate of fruit treated with MAP was lower than the control and AV-treated fruit. Similarly, ethylene production of MAP and AV-treated fruit was lower than the control. At the end of storage, the highest hue angle was obtained from the control, whereas the lowest hue angle was measured in AV + MAP. Decay rate of AV and MAP-treated fruit was lower than the control. Vitamin C, total flavonoids, total monomeric anthocyanin and antioxidant activity of fruit treated with AV and MAP was higher than the control. The astringency of AV and AV + MAP-treated fruit was higher than the control at the end of storage. This study revealed that AV gel and MAP treatments were effective in maintaining quality and bioactive compounds of cherry laurel fruit.

Ultrasound as a potential process to tenderize beef: Sensory and technological parameters

In this study, the effects of high intensity ultrasound (HIU), applied after storage, on the physical, microstructural, and sensory characteristics of beef were evaluated. Samples of four beef m. Longissimus dorsi muscle were stored in vacuum at 4 °C for 0, 7 or 14 days and then ultrasonicated (40 kHz, 11 W/cm2) for 60 min. Beef stored for 7 d prior to ultrasonication displayed increased pH and luminosity, reduced redness and saturation value, higher hue angle, and variable changes in water holding capacity. Shear force of sonicated meat was lower than that of control samples at all storage times. HIU also increased the tenderness and fragmentation of meat (P < 0.05) measured by texture profile analysis. The microstructure of sonicated meat showed a visible reduction in the size of fascicles, greater interfibrillary spaces, and thinner endomysium. These effects were enhanced with the storage of meat previous to HIU treatment. Meat stored for 14 d and then treated with ultrasound was perceived to have a more intense fresh meat smell and oily flavor (P < 0.05). However, it was also perceived to be a paler grayish brown color compared to control samples stored for the same duration. Ultrasonicated meat also presented a greater intensity of metallic taste (P < 0.05) and a more tender and moist texture (P < 0.05). Overall, application of HIU of meat after meat was stored affects textural and microstructural properties and accelerates aging without negative impacts on other technological and sensory attributes. Therefore, HIU application after storage has potential as a safe method for tenderizing bovine meat when handled under the conditions in this study.

The Effect of Long-Term Frozen Storage on the Quality of Meat (Longissimus thoracis et Lumborum) from Female Roe Deer (Capreolus capreolus L.)

The objective of this study was to determine the quality of meat (Longissimus thoracis et lumborum) from 10 female roe deer (Capreolus capreolus L.), which was vacuum-packaged, frozen-stored (−26°C) for 6, 10, and 12 months, and compared with fresh, nonfrozen meat. Roe deer (aged 3 to 5 years) were hunter-harvested in north-eastern Poland in December and January during the same hunting season. Frozen storage did not affect the proximate chemical composition of meat (except for ash content). An analysis of the physicochemical properties of meat revealed that frozen-stored meat was characterized by a darker color, a higher hue angle, lower ability to bind its own and added water, and lower cooking loss compared with nonfrozen meat. The values noted for meat samples that were stored in the freezer for 12 months (increase in pH, considerable decrease in water-holding capacity, and first symptoms of flavor deterioration) indicate that frozen roe deer meat should be stored for no more than 10 to 12 months to maintain its high quality.

Influence of cyanidin glycosylation patterns on carboxypyranoanthocyanin formation

Anthocyanins can condense with compounds having enolizable groups to form pyranoanthocyanins. These pigments are less susceptible to degradation and color changes associated with nucleophilic addition common to anthocyanins. This study aimed to evaluate the impact of glycosylation patterns of anthocyanins on carboxypyranoanthocyanin formation. Nine cyanidin derivatives were isolated by semi-preparative HPLC. Pyruvic acid was added to induce pyranoanthocyanin formation. Composition (HPLC-MS/MS), spectra (absorbance 380–700 nm), and color (CIEL*c*h*) of solutions were monitored during 31 days storage at 25 °C. Cyanidin-3-glycosides with 1 → 6 disaccharides produced the highest pyranoanthocyanin yield (∼31%), followed by Cyanidin-3-monoglycosides (∼20%); 1 → 2 disaccharides produced the least proportions of pyranoanthocyanins (5–7%). Cyanidin-3-arabinoside converted to pyranoanthocyanins but degraded quickly (3% yield) under these conditions. No pyranoanthocyanins were formed from Cyanidin-3-sophoroside-5-glucoside. Glycosyl bonds were more critical than the size of the substitution alone, further supported by Cyanidin-3-(glucosyl)-(1 → 6)-(xylosyl-(1 → 2)-galactoside) yield (11%). Pyranoanthocyanins were hypsochromically shifted and had higher hue angles than their respective anthocyanins.

Effect of high-pressure treatments on proteolysis, volatile compounds, texture, colour, and sensory characteristics of semi-hard raw ewe milk cheese

High pressure (HP) offers potential industrial applications in cheese preservation, but it is essential to provide knowledge concerning their effects on the ripening process and sensory characteristics. In this study, we investigated the effect of different HP treatments (200–500MPa at 14°C for 10min on day 7) on proteolysis, texture, colour, volatile compounds and sensory characteristics of semi-hard raw ewe milk cheese. HP treatments did not affect pH or dry matter values of 60-day-old cheeses. Treatments at pressure levels up to 400MPa led to significant (P<0.01) increases in the total free amino acids (FAA) content at 60days, compared to control cheese, although the cell-free aminopeptidase activity was lower. HP retarded the formation of some volatile compounds in cheeses, the number of compounds affected by HP being higher as the pressure level increased. Cheeses pressurized at 300–500MPa had lower levels of 2-butanone, 2-butanol, 2-propen-1-ol, 1-butanol and acetic acid than control cheese, cheeses pressurized at 400–500MPa lower levels of 1-propanol, 2-pentanol, and butyric and hexanoic acids, and cheeses pressurized at 500MPa lower levels of ethanol, 3-methyl-1-butanol and 3-methyl-2-buten-1-ol. All HP-treated cheeses showed higher fracturability values, and higher Hue angle and lower a* values than control cheese. Despite the differences detected by instrumental analyses between HP-cheeses and control cheese, few significant differences were found between the sensory characteristics of HP-cheeses and control cheese. Only the pressurization of cheese at 500MPa affected significantly (P<0.01) some of the sensory characteristics, with a negative effect on taste intensity but a positive effect on aroma quality.In summary, HP treatments at 200 and 300MPa showed the mildest effects on the characteristics of semi-hard raw ewe milk cheese. HP treatment of this cheese variety at 300, 400 and 500MPa prevented late blowing defect caused by Clostridium tyrobutyricum (Ávila et al., 2016, Food Microbiol. 60, 165–173). Thus, it may be concluded that HP treatment at 300MPa is the most adequate procedure, able to prevent late blowing with minimum changes in cheese characteristics.

Effect of pre-treatment and different drying methods on the physicochemical properties of Carica papaya L. leaf powder

Abstract The Carica papaya L. leaves are often considered as wastes, but they are actually beneficial for health. The study was aimed to explore the effect of pre-treatment and different drying methods on the physicochemical properties of Carica papaya L. leaves powder. The leaves were blanched in hot water before they went through the drying process, which consisted of oven drying (OD), shade drying (SD) and freeze drying (FD). The results showed that blanching helped in improving the powder physical properties and preserving the phenolic compounds and ascorbic acid. Blanching also increaseed the bulk density and improved flowability in all drying methods, except for FD. Pretreated oven dried powder resulted in better physicochemical properties in other drying methods, except for vitamin C content, which was higher in freeze-dried powder. OD at 40 °C resulted in powder with the maximum bulk density (659 kg/m 3 ), excellent flowability, the least lightness and color change, the highest hue angle and maximum retention of total phenolic content (374 mg GAE/g).