Volatile composition and sensory quality of Spanish pomegranates (Punica granatum L.)

Influence of Pomegranate Appearance Attributes on Consumer Choice, and Identification of Barriers and Drivers for Consumption

In a prepurchase situation, consumers base their choice decision on external fruit characteristics, from which they infer internal characteristics. This study investigates consumer preference for pomegranate appearance using a choice-based conjoint analysis with 320 participants. We created 27 images of pomegranates that differed in varietal characteristics: colour (yellow, bicoloured, and red), shape (round, oval, and flattened), and calyx shape (open, semi-open, and closed). Colour was by far the most important factor for consumers, followed by fruit shape and calyx shape. Two preference profiles were identified. Most consumers liked bicolour and red pomegranates equally, and rejected yellow ones, while a smaller group concentrated their choice on bicolour pomegranates. In terms of fruit and calyx shape, oval and flattened fruit and open calyx were the most preferred by both consumer groups. Barriers and drivers for consumption were also investigated. There is still plenty of room to increase pomegranate consumption. Greater availability of pomegranates and ready-to-eat arils in grocery shops, obtaining new unseeded/easier-to-peel varieties, and providing a sensory label would help to overcome current barriers. Marketing campaigns should focus on a pomegranate's health benefits and its versatility in consumption.

Taste and chemical composition as drives for utilitarian redundancy and equivalence: a case study in local medical systems in Northeastern Brazil

BACKGROUND

We aimed to verify whether the taste and chemical composition influence the selection of plants in each medicinal category, whether within a socio-ecological system or between different socio-ecological systems. To this end, we use the theoretical bases of the Utilitarian Redundancy Model and the Utilitarian Equivalence Model. We studied the local medical systems of four rural communities in northeastern Brazil, used as models to test our assumptions.

METHODS

The data on medicinal plants and local therapeutic function were obtained from semi-structured interviews associated with the free-listing method, allowing to generate indexes of similarity of therapeutic use between the plants cited in each region. During the interviews, each informer was also asked to report the tastes of the plants cited. Subsequently, we classified each plant in each region according to the most cited taste. The data about the chemical composition of each plant were obtained from a systematic review, using Web of Knowledge and Scopus databases.

RESULTS

Pairs of plants with similar tastes are 1.46 times more likely to have the same therapeutic function within a local medical system (redundancy), but not between medical systems (equivalence). We also find that chemical compounds are not primarily responsible for utilitarian redundancy and equivalence. However, there was a tendency for alkaloids to be doubly present with greater expressiveness in pairs of equivalent plants.

CONCLUSIONS

The results indicate that each social group can create its means of using the organoleptic characteristics as clues to select new species as medicinal. Furthermore, this study corroborates the main prediction of the Utilitarian Equivalence Model, that people in different environments choose plants with traits in common for the same functions.

Chemical Composition, Antioxidant Activity, and Sensory Characterization of Commercial Pomegranate Juices

We undertook a qualitative and quantitative assessment of the bioactive compounds, volatile substances, sensory profile, and antioxidant activity of eight different commercial pomegranate juices (PJs) differing by cultivation area, processing (from concentrate (CPJ) or not (NCPJ)), and microbial stabilization. Punicalins were the main ellagitannins, whereas the predominant anthocyanin was cyanidin 3,5-diglucoside, followed by cyanidin 3-glucoside. Total phenols, tannins, hydrolyzable tannins, and anthocyanins in the investigated juices ranged from 1379.9 to 3748.8 mg gallic acid equivalent (GAE)/L, 394.8 to 895.2 mg GAE/L, 150.8 to 2374.2 mg ellagic acid/L, and 0 to 281 mg cyanidin 3-glucoside/L, respectively. Antioxidant activity, determined by DPPH^•, FRAP, and ABTS, was positively correlated with the total phenolic compounds and hydrolyzable tannins. Alcohols, acids, and furans were the volatile groups that best described the differences between juices. The most abundant volatile compound was 3-Furfural (8.6–879.9 µg/L) in those juices subjected to the concentration process and to high-temperature short-time (HTST) treatment, whereas it was not present in juice subjected to high-pressure processing (HPP). Processing also affected the juices’ sensory attributes: NCPJs were characterized by ‘red–purple’, ‘pomegranate fruit’, ‘fresh fruit’, and ‘overall intensity’ notes, while in CPJs these notes were not revealed or were masked by those related to heat treatment. Our results provide useful information on the importance of extraction methods and on the overall quality of PJ for the food industry.

Taste Beats Reputation in New Food Products Choice: The Case of Ready-to-Eat Pomegranate among Young Consumers in Veneto Region (Italy)

This study investigates the preferences for ready-to-eat pomegranate arils in Italy through a discrete choice experiment (DCE) on 264 young consumers in Italy. The aim is to estimate consumers’ willingness to pay (WTP) for the reputational attributes of the product (e.g., the product origin and sales channel) and to discriminate the elicited preferences between tasting and non-tasting situations. To this purpose, a random parameter logit model was employed to assess the heterogeneity in consumer preferences. The results suggest that non-tasters attach a relevant value to the reputational attributes (e.g., +75% WTP for Italian origin). Moreover, considering the sensory features of the products, we found that consumers in this group discriminate against the proposed samples only through their visual characteristics: they prefer the sample with the largest size and red colored arils. In addition, we found that the tasting experience reduced the value attached to the reputational attributes (e.g., −50% WTP for local origin) for consumers, compared to non-tasting situation, thus shifting their preference to the samples that they appreciated the most (high liking). Specifically, we found that consumers in the tasting group preferred the product sample with the highest level of sweetness and the lowest level of sourness and astringency, showing a higher preference for sweetness. The findings contribute to the literature on consumers’ behavior on new food products (NFPs), showing that reputational attributes lose value after the tasting experience. In contrast, the sensory features of the NFPs can help tasters to reduce the information asymmetry, which traditionally represents a hurdle in purchases for new consumers. However, this depends on the individuals’ subjective preferences, as demonstrated by the significant effect of liking levels in discriminating consumers’ choices. To conclude, although these results cannot be extended to the general population, they may give some interesting insights about future trends of NFP demand.

Elucidation of Volatiles, Anthocyanins, Antioxidant and Sensory Properties of cv. Caner Pomegranate (Punica granatum L.) Juices Produced from Three Juice Extraction Methods

This study deals with the characterization of the phytochemical profiles and antioxidant activities of cv. Caner pomegranate (Punica granatum) juices obtained from three different juice extraction methods including halved pomegranate (HPJ), arils (AJ), and macerated arils (MAJ) extraction for the first time. It was found that the type of the juice extraction process had substantial effects on the volatiles, anthocyanin compositions, and antioxidant activities of the samples. Results showed that the AJ sample (593 mg L^-1) had more anthocyanin compounds followed by HPJ (555 mg L^-1) and MAJ (408 mg L^-1) samples. GC-MS analysis revealed a total of 34 volatile compounds. The highest number of volatiles was found in the MAJ sample (1872 µg L^-1); thus, the aril maceration process played an important role in increasing the volatiles as compared to the HPJ (751.8 µg L^-1) and AJ (710.7 µg L^-1) samples. Sensory analysis showed that the HPJ sample was the most preferred and its general impression was higher as compared to the AJ and MAJ samples. The findings of this study elucidated that the juice extraction technique had a significant influence on the phytochemical profiles, sensory quality, and antioxidant activity of pomegranate juices.

Effect of CO2 Preservation Treatments on the Sensory Quality of Pomegranate Juice

Due to the interest in identifying cost-effective techniques that can guarantee the microbiological, nutritional, and sensorial aspects of food products, this study investigates the effect of CO2 preservation treatment on the sensory quality of pomegranate juice at t0 and after a conservation period of four weeks at 4 °C (t28). The same initial batch of freshly squeezed non-treated (NT) juice was subjected to non-thermal preservation treatments with supercritical carbon dioxide (CO2), and with a combination of supercritical carbon dioxide and ultrasound (CO2-US). As control samples, two other juices were produced from the same NT batch: A juice stabilized with high pressure treatment (HPP) and a juice pasteurized at high temperature (HT), which represent an already established non-thermal preservation technique and the conventional thermal treatment. Projective mapping and check-all-that-apply methodologies were performed to determine the sensory qualitative differences between the juices. The volatile profile of the juices was characterized by gas chromatography-mass spectrometry. The results showed that juices treated with supercritical CO2 could be differentiated from NT, mainly by the perceived odor and volatile compound concentration, with a depletion of alcohols, esters, ketones, and terpenes and an increase in aldehydes. For example, in relation to the NT juice, limonene decreased by 95% and 90%, 1-hexanol decreased by 9% and 17%, and camphene decreased by 94% and 85% in the CO2 and CO2-US treated juices, respectively. Regarding perceived flavor, the CO2-treated juice was not clearly differentiated from NT. Changes in the volatile profile induced by storage at 4 °C led to perceivable differences in the odor quality of all juices, especially the juice treated with CO2-US, which underwent a significant depletion of all major volatile compounds during storage. The results suggest that the supercritical CO2 process conditions need to be optimized to minimize impacts on sensory quality and the volatile profile.

Optimization of roasting conditions in hydroSOStainable almonds using volatile and descriptive sensory profiles and consumer acceptance

HydroSOStainable almonds are harvested from trees cultivated under controlled water stress by using a regulated deficit irrigation (RDI) strategy. The aim of this study was to investigate consumers' perception to select the best roasting temperature for the hydroSOStainable almonds and its correlation with volatile compounds, descriptive sensory attributes, instrumental color, and texture. Thirty-five volatile compounds were identified and the key compounds for the roasting process were 2,5-dimethylpyrazine, furfural, and trimethyl pyrazine. Pyrazines, furans and, in general, volatiles were higher in hydroSOStainable almonds than in control. Instrumental color and trained panel showed that almonds roasted at 190 °C presented intense color and burnt notes in both irrigation treatments, while almonds roasted at 150 °C were under-roasted. Principal component analysis (PCA) grouped together the samples of the same irrigation treatment, but separated samples roasted at different temperatures. Partial least square regression (PLS) results indicated that consumers overall liking was positively linked to specific volatiles (alkanes, alcohols, aldehydes, and furans) and sensory attributes (sweetness, roasted, almond ID, nutty, hardness, and crispiness), but, negatively correlated with pyrazines, bitterness, astringency, woody, and burnt flavor notes. Penalty analysis showed that almonds roasted at 150 and 190 °C were penalized due to low roasted aroma and soft almonds, and over-roasted samples with too intense color and burn notes, respectively. While no penalization being found for almonds roasted at 170 °C. Overall, roasting at 170 °C for 10 min in a convective oven were the optimum conditions for roasting Vairo almonds. PRACTICAL APPLICATION: This research describes the link between physicochemical and sensory analysis of roasted almonds giving evidence about possible sensory quality markers. Besides, it provides valuable information for the food industry to produce roasted almonds that meet consumer demands and for the agricultural sector by encouraging reduction of irrigation water consumption by almond trees.

Volatile Composition and Sensory Attributes of Smoothies Based on Pomegranate Juice and Mediterranean Fruit Purées (Fig, Jujube and Quince)

To increase the intake of fruits and vegetables—especially among young people—the food industry is trying to develop new, easy-to-eat and long-shelf-life products, such as smoothies. Nowadays, consumers are choosing their foods based not only on nutritional/functional properties (content of polyphenols, vitamins, minerals, among others), but also on sensory attributes. The aim of this study was to investigate the volatile composition by HS-SPME and the sensory profile by descriptive sensory analysis of novel smoothies prepared by blending fig, jujube or quince purée with pomegranate juices (cv. Mollar de Elche or Wonderful) at two ratios purée:juice (40:60 or 60:40). Twenty-three volatile compounds were identified by GC-MS and classified as alcohols, aldehydes, esters, furans, ketones, terpenes and terpenoids. Among volatile compounds, the five predominant ones in the studied smoothies were: (i) 5-HMF (30.6%); (ii) 3-hexen-1-ol (9.87%); (iii) hexanal (9.43%); (iv) 1-hexanol (8.54%); and (v) 3-octanone (7.67%). Fig smoothies were sweet and had flavor and volatiles related to fig, pomegranate, and grape. While jujube products were bitter and had jujube and pear notes. Finally, quince smoothies were consistent, sour and had quince, apple and floral notes. Thus, the type of fruit purée used clearly determined the flavor of the final product. The smoothies prepared with Mollar de Elche pomegranate juice were characterized by having high intensity of pear odor/aroma and consistency, and the Wonderful smoothies were characterized by lower consistency and more intense pomegranate aroma and sourness.

Potential of the Probiotic Lactobacillus Plantarum ATCC 14917 Strain to Produce Functional Fermented Pomegranate Juice

In this research survey the application of probiotic strain Lactobacillus plantarum ATCC 14917 in pomegranate juice fermentation is sought. Pomegranate juice was fermented for 24 h and then it was stored 4 for 4 weeks. Cell viability retained in high levels after the 24 h of fermentation and storage for 4 weeks (above 8.8 log cfu/mL), while fermented pomegranate juice was scored better at the 4th week of storage compared to non-fermented pomegranate juice. The probiotic strain was effective regarding lactic acid fermentation as was proved through sugar and organic acids analysis. Concentration of ethanol was maintained at low levels (0.3–1% v/v). Fermented pomegranate juice contained more and in higher percentages desirable volatile compounds (alcohols, ketones and esters) even at the 4th week of cold storage compared to non-fermented juice. Antioxidant activity (150.63 mg Trolox equivalent (TE)/100 mL at the 2nd week) and total phenolic content (206.46 mg gallic acid equivalents (GAE)/100 mL at the 2nd week) were recorded in higher levels for all the storage time compared to non-fermented juice.

Consumers' Opinion on Dried Pomegranate Arils to Determine the Best Processing Conditions

Consumers' preference is essential to improve processed food products quality, but small companies sometimes lacks knowledge or tools to develop consumer studies. The aim of the present study was to investigate consumers' insight to recommend the best drying methodology for pomegranate arils. With the aim of providing information that industry can correlate to the drivers of liking, descriptive sensory characteristics, and volatile compounds of the samples were determined and related with consumers' responses. A total of 19 volatiles of dehydrated pomegranate arils were determined using solid-phase microextraction and gas chromatography-mass spectrometry. Partial least square regression (PLS) results indicated that consumers overall liking was positively correlated with "pom ID", "sweet", and "fruity" attributes, and also volatile compounds of the esters family. Overall liking was negatively correlated with the "off-flavor" and "burnt" attributes, related to the furan compounds family. Penalty analysis indicated that the sample corresponding with the current commercial product needed improvement on the "pom ID", "fruity", and "sweetness" parameters. All the samples processed using the proposed new drying techniques were more liked than the commercial sample, highlighting a sample dried using pre-osmotic dehydration in Wonderful concentrate pomegranate juice. PRACTICAL APPLICATION: Consumers' preference is essential to improve processed food products quality, but small companies sometimes lack knowledge or tools to conduct consumer studies. The present study provides useful information to understand consumers' preferences of a healthy product such as pomegranate dehydrated arils. Also, the link of physico-chemical and sensory tools is clearly described, providing information about possible sensory quality indicators.

Influence of deficit irrigation and crop load on the yield and fruit quality in Wonderful and Mollar de Elche pomegranates

BACKGROUND

The working hypothesis of the present study was that, by proper simultaneous control of irrigation (hydroSOStainable products) and crop load (thinning), it is possible to promote the accumulation of bioactive compounds and improve fruit appearance (size and weight). The effects of (i) irrigation status [T0, 120% ETc (estimated crop evapotranspiration); T1, 60% ETc during fruit growth and ripening] and (ii) crop load (A0, no thinning; A1, thinning) on yield and fruit quality were evaluated in two pomegranate cultivars (Wonderful, Wond and Mollar de Elche, ME).

RESULTS

Thinning was effective in increasing the size and weight of fruits. Unfortunately, neither punicalagin, nor total polyphenolic content were positively affected by irrigation and thinning. T1A1 Wond fruits were characterized by high sugar content (glucose and fructose), together with high fruit size and weight. Furthermore, T1A1 ME fruits were characterized by high contents of alcohols and monoterpenoids (providing vegetal and citric flavor notes) and key sensory attributes (color, fruity and fresh pomegranate).

CONCLUSION

The final recommendation was to use the treatment T1A1 [simultaneous combination of deficit irrigation during fruit growth and ripening (T1) and thinning (A1)], although the positive results were cultivar-dependent. © 2017 Society of Chemical Industry.

Quality Parameters, Volatile Composition, and Sensory Profiles of Highly Endangered Spanish Citrus Fruits

There is very little information available on the chemical composition and the quality attributes of the citrus species studied which are truly endangered in Spain. None of the fruits studied is available for commercial purposes, which is the main interest and novelty of this study. The aim of this work was to fully describe the morphology, volatile composition, and sensory profile of traditional citrus fruits: sour lime (SoLi), sweet lime (SwLi), and sweet lemon (SwLe), to have the information to convince farmers and growers to cultivate these fruits again. The predominant sugar was fructose while citric acid prevails in SoLi and SwLe. Regarding volatiles compounds, monoterpenes, monoterpenoids, and esters predominated in the juices, and these three families plus sesquiterpenes in the peels. The juice of SoLi presented the highest content of esters (14.8%), SwLi juice presented similar values of both monoterpenes and monoterpenoids (46.1 and 46.0%, resp.), and SwLe juice had the highest content of monoterpenes (72.2%). The results demonstrated the high potential of these citrus materials for the agrofood industry. Therefore, it will be possible to recover these vegetal materials at risk of disappearing for potential uses by the food industry and simultaneously help maintaining the biodiversity.

Effects of the plant volatile trans‑2-hexenal on the dispersal ability, nutrient metabolism and enzymatic activities of Bursaphelenchus xylophilus

Bursaphelenchus xylophilus causes pine wilt disease (PWD), which severely damages pine species. The plant volatile trans‑2-hexenal has strong activity against nematodes, although the precise mechanism of this inhibitory action remains unclear. In this paper, the fumigant effects of the LC₁₀ and LC₃₀ of trans‑2-hexenal on B. xylophilus were demonstrated. The trans‑2-hexenal treatments significantly inhibited the dispersal ability of nematodes. The results also indicated that trans‑2-hexenal affects the metabolism of nutrients and the activity of digestive enzymes. Among detoxifying enzymes, after treatment with trans‑2-hexenal, glutathione S-transferase activity increased significantly and general esterase activity decreased significantly. Based on these results, trans‑2-hexenal disturbs the normal physiological and biochemical activities of this nematode. These results provide valuable insight into the nematicidal mechanisms of trans‑2-hexenal.

Lactic acid fermentation drives the optimal volatile flavor-aroma profile of pomegranate juice

Pomegranate juice (PJ) fermented with Lactobacillus plantarum C2, POM1, and LP09, unstarted-PJ, and raw-PJ were characterized for the profile of the volatile components (VOC) by PT-GC-MS. Lactic acid fermentation through selected strains enhanced the flavor profile of PJ. Concentrations of desired compounds (e.g., alcohols, ketones, and terpenes) were positively affected, whereas those of non-desired aldehydes decreased. Unstarted-PJ mainly differentiated from fermented PJs for the highest levels of aldehydes and sulfur compounds, and in lesser extent of furans, whereas alcohols, ketones, and alkenes followed by terpenes and benzene derivatives mainly differentiated fermented PJs. As expected, the lowest level of VOC was found in raw-PJ. VOC profile reflected on the sensory features of fermented PJs, unstarted-PJ, and raw-PJ, which were evaluated using a consensus modified flavor profile based on 13 attributes. Fermented PJs were mainly discriminated by the higher intensity of floral, fruity and anise notes than the controls.

Volatile Composition of Smoked and Non-Smoked Iranian Rice

In this work, the volatile profiles of smoked and non-smoked Iranian rice were identified, and their relative abundance was calculated and compared. Headspace solid-phase microextraction together with gas chromatography-mass spectrometry (SPME-GC-MS) were used to extract and identify the volatile compounds. The main groups of volatiles in Iranian rice were aldehydes, ketones, phenol derivatives, furans, linear hydrocarbons, esters and terpenes. The chemical family aldehydes was the most abundant one in the profile of non-smoked rice, while phenol derivatives and furans predominated in smoked samples. This study is the first one reporting comparative data of volatile compounds between smoked and non-smoked Iranian rice.

Physico-chemical, nutritional, and volatile composition and sensory profile of Spanish jujube (Ziziphus jujuba Mill.) fruits

BACKGROUND

Jujube fruit is eaten mostly fresh, but may be dried (Chinese dates and tea) or processed into confectionary recipes in bread, cakes, compotes, and candy. Given that the quality of jujube available on the market differs on account of various factors such as geographical environment, cultivar, processing conditions, and storage conditions, and that, for consumers, flavour and nutrition properties of jujube represent the major parameters in determining the quality of jujube, the main goal of this study were to determine the main physico-chemical properties of jujube fruits, sugars and organic acids profiles, protein, mineral constituents, volatile composition and sensory profile of jujube fruits. This would allow breeders to select cultivars with higher levels of nutrients and also enable increasing dietary intake by consumers.

RESULTS

Investigations showed that jujube fruit weight ranged from 4.8 to 29.3 g fruit(-1) . Four sugars (glucose, fructose, sucrose and sorbitol) and four organic acids (citric, malic, ascorbic and succinic acids) were identified and quantified by high-performance liquid chromatography in jujube fruits. Potassium, calcium and magnesium were the major mineral constituents in jujube fruits. Fifteen volatiles compounds were found in the aroma profile of jujube fruits (nine were aldehydes, three terpenes, one ester, one ketone and one linear hydrocarbon).

CONCLUSION

The results showed that Spanish jujube cultivars studied are a good source of vitamin C, and they have a low content of Na. The jujube cultivar with the most appreciated quality by consumers was GAL; the GAL fruits were sweet, crunchy, and had high intensities of jujube ID and apple flavour a long after-taste. Therefore, jujube grown in Spain has a great potential to be exploited for functional foods. © 2015 Society of Chemical Industry.

Sensory and nutritional attributes of pomegranate juices extracted from separated arils and pressed whole fruits

BACKGROUND

The present study aimed to compare the sensory and nutritional attributes of 'Wonderful' pomegranate juices extracted from separated arils with those from pressed whole fruits.

RESULTS

Five different sensory tests were conducted to evaluate the flavor quality of 'Wonderful' pomegranate juices. Consumer acceptance tests revealed that juice from separated arils achieved significantly higher likability scores than that from whole pressed fruits. Furthermore, preference tests revealed that 84% of the tasters preferred the juice extracted from separated arils whereas only 16% preferred the juice from whole pressed fruits. Sensory discrimination tests (triangle tests) revealed that tasters significantly distinguished between the two juices at P ≤ 0.01. Descriptive tests by a trained panel and sensory analysis with an electronic tongue demonstrated that juice from whole pressed fruits was more astringent and had a stronger aftertaste than juice from separated arils. Juice from pressed whole fruits contained significantly higher levels of phenols and hydrolysable tannins, which led to higher astringency.

CONCLUSIONS

Pomegranate juice extracted from separated arils was less astringent and more preferred by tasters than juice from whole pressed fruits. Nonetheless, juice from separated arils has lower nutritional benefits.

Quality attributes of pistachio nuts as affected by rootstock and deficit irrigation

BACKGROUND

In this work, the influence of two regulated deficit irrigation (RDI) treatments and three different rootstocks on the quality of pistachios was evaluated by analyzing different parameters: morphological analysis, physicochemical analysis and sensory analysis.

RESULTS

The results obtained in terms of the choice of rootstock revealed that Pistacia atlantica had increased production yields, nut weight, mineral content, higher intensities of characteristic sensory attributes and a higher degree of consumer satisfaction, than the other rootstocks studied. Moreover, the results established that the application of RDI on pistachio cultivation had no significant influence on production yield, weight, size, colour, water activity or mineral composition. Furthermore, T1 treatment (stem water potential < -1.3 MPa) resulted in higher intensities of characteristic sensory attributes and a greater level of satisfaction among international consumers.

CONCLUSION

These results confirm that the application of deficit irrigation (T1) contributes to an increase in overall product quality. Furthermore, Pistacia atlantica rootstock provided better yield and quality than the other rootstocks studied.

Quality changes of fresh-cut pomegranate arils during shelf life as affected by deficit irrigation and postharvest vapour treatments

BACKGROUND

The effect of two sustained deficit irrigation (SDI) strategies, compared to a control, on postharvest physicochemical, microbial, sensory quality attributes and anthocyanin content of fresh-cut pomegranates arils throughout 18 days at 5 °C was studied. Furthermore, the effect of vapour treatments (4, 7 and 10 s) compared to a conventional sanitizing treatment with NaClO on such quality parameters in combination with the preharvest treatments was also studied.

RESULTS

According to sensory analyses, the shelf life of arils from control and SDI-irrigated fruit was established in 14 and 18 days at 5 °C, respectively, showing 4 and 7 s vapour treatment time the best sensory quality. No significant change was observed in physicochemical quality attributes, across all treatments during storage, while low microbial loads were registered (<3 log CFU g(-1)) after shelf life. Postharvest treatments that had least effect on anthocyanin content on processing day were 7 and 10 s.

CONCLUSION

Vapour treatments of 7-10 s applied to pomegranate arils led to an extended shelf life up to 18 days at 5 °C with better results in SDI-irrigated samples with a water saving of 6-11%.

Influence of processing on pomegranate (Punica granatum L.) juice flavor and aroma

BACKGROUND

The objective of this study was to determine the effect of technological treatment on pomegranate juice flavor characteristics, aromatic compounds and physicochemical properties. Fresh, fresh frozen, pasteurized and reconstituted juice samples were made from Wonderful variety pomegranates. The samples were analyzed for their flavor profiles, aromatic compound content and physicochemical parameters (total soluble solids, pH, acidity and total phenolic content).

RESULTS

The results indicated differences among the samples' flavor characteristics. The most differentiated was the reconstituted sample with fermented and brown flavors, while fresh, fresh frozen, and pasteurized samples did not vary as much. Concentration of aromatic compounds was lower than expected. However, this finding was in line with the flavor profiles of the samples. Some flavors as well as total phenolic content were found to be lower than what has been previously reported, and this may be the result of a number of variables such as the season, growing region and subspecies of the fruit variety.

CONCLUSIONS

Processing has an effect on pomegranate juice properties; however, the effect is different depending on the processing method chosen. Drying and reconstituting pomegranate seeds have an impact on flavor and aromatic compounds, as well as total phenolic content.

Phytochemical and quality attributes of pomegranate fruits for juice consumption as affected by ripening stage and deficit irrigation

BACKGROUND

Pomegranate (PG) is a drought resistant crop, thriving well with scarce water resources. The non-climateric character of PG remarks the importance of determining the optimum harvest time to improve quality and phytochemical properties of PG.

RESULTS

The influence of two different irrigation treatments on physico-chemical and phytochemical parameters of PG was assessed. Control trees (T0) were over irrigated (105% ETo). From the beginning of the second half of rapid fruit growth period to the last harvest, T1 plants were subjected to sustained deficit irrigation (33% ETo). Results indicated that T1 fruits exhibited a darker and more intense garnet colour than T0 fruits, but deficit irrigation led to a significant decrease in total fruit yield and number of total fruits per tree. T1 fruits showed similar bioactive quality than T0 fruits; however, T1 fruits advanced the optimal harvest time by about 7-8 days with respect to T0 fruits.

CONCLUSIONS

Late-pomegranate fruits were rich in phytochemicals and could be of great interest to the juice industry. Knowledge of these trends is important, especially to improve PG juice quality and to contribute to the sustainability of PG culture with respect to water, fertiliser and energy saving.

Determination of the antiradical activity and kinetics of pomegranate juice using 2,2-diphenylpicyrl-1-hydrazyl as the antiradical probe

Whole fruit pomegranate (Punica granatum L.) juice of the 'Wonderful' cultivar was characterized through the elucidation of its antiradical kinetics and activity using 2,2-diphenyl-1-picrylhydrazyl as the antiradical probe. Time-dependent concentration of 2,2-diphenyl-1-picrylhydrazyl during its reduction by the juice has been adjusted through a non-linear parametric fitting. Determined total antiradical activity was high, able to reduce 84.58 µmol/l of 2,2-diphenyl-1-picrylhydrazyl per concentration unit of juice (µl/ml), equivalent to a concentration of 42.29 mmol/l of ascorbic acid (or Trolox). Partial antiradical activities due to the fast-, medium- and slow-kinetics were 49.09, 18.16 and 17.33 µmol/l of reduced 2,2-diphenyl-1-picrylhydrazyl per concentration unit of juice (µl/ml), respectively. The corresponding rate constant for the fast-, medium- and slow-kinetics were κ 1 = 6.03, κ 2 = 0.169 and κ 3 = 0.0094 (μl l)/(ml µmol min), respectively. This methodology allows characterization of samples through the accurate determination of the kinetics of their antiradical features, avoiding the use of empirical approximations that hinder the realistic comparison between extracts independently of their origin.

Pomegranate juice adulteration by addition of grape or peach juices

BACKGROUND

Pomegranate juice has gained a high reputation for its health properties and consequently is now a highly demanded product. However, owing to the limited production and high price of fresh pomegranates, adulteration of pomegranate juice seems to be happening. Hence it is imperative to establish criteria for detecting adulteration.

RESULTS

Addition of grape juice significantly increased the contents of Ca, Mg and Fe and especially tartaric acid and proline and simultaneously decreased the content of K. Addition of peach juice up to 10% (v/v) only resulted in a significant increase in sucrose content. Regarding the volatile composition, adulteration of pomegranate juice with grape juice resulted in significant increases in acetic acid, isoamyl butyrate and especially 1-hexanol and linalool, while adulteration with peach juice resulted in significant increases in butyl acetate, isobutyl butyrate, benzyl acetate and especially isoamyl butyrate.

CONCLUSION

The control protocols used in this study can serve as a basis for identification of pomegranate juice adulteration. It is important to highlight that it is necessary to simultaneously analyze and have results from several parameters to conclude that a particular pomegranate juice has been adulterated by mixing with another fruit juice.

The flavor of pomegranate fruit: a review

Despite the increasing commercial importance of pomegranate, especially because of its recently discovered health-promoting benefits, relatively little is yet known regarding its sensory quality and flavor preferences, or about the biochemical constituents that determine its sensory characteristics. The perceived flavor of pomegranate fruit results from the combination of various taste, aroma and mouthfeel sensations. The taste is governed mainly by the presence of sugars (glucose and fructose) and organic acids (primarily citric and malic acids). The aroma evolves from the presence of dozens of volatiles, including alcohols, aldehydes, ketones, and terpenes, which provide a mixture of various 'green', 'woody', 'earthy', 'fruity', 'floral', 'sweet' and 'musty' notes. In addition, the sensory satisfaction during the eating of pomegranate arils is complemented by various mouthfeel sensations, including seed hardness and astringency sensations. In the present review we will describe the sensory quality and flavor preferences of pomegranate fruit, including the genetic diversity in flavor characteristics among distinct varieties. In addition, we will describe the dynamic changes that occur in fruit flavor during fruit ripening and postharvest storage.