Juice Aroma Research Articles

Processing and Storage Effects on Orange Juice Aroma: A Review

Freshly squeezed orange juice aroma is due to a complex mixture of volatile compounds as it lacks a specific character impact compound. Fresh hand-extracted juice is unstable, and thermal processing is required to reduce enzyme and microbial activity. Heating protocols range from the lightly heated not from concentrate, NFC, to the twice heated, reconstituted from concentrate, RFC, juices. Thermal processing profoundly effects aroma composition. Aroma volatiles are further altered by subsequent time-temperature storage conditions. Heating reduces levels of reactive aroma impact compounds such as neral and geranial, and creates off-flavors or their precursors from Maillard, Strecker, and acid catalyzed hydration reactions. Off-flavors such as 4-vinylguaiacol, p-cymene, and carvone are the products of chemical reactions. Other off-flavors such as butane-2,3-dione, guaiacol, and 2,6-dichlorophenol are indicators of microbial contaminations. Since most orange juice consumed worldwide is processed, the goal of this review is to summarize the widely scattered reports on orange juice aroma differences in the three major juice products and subsequent aroma changes due to packaging, storage, and microbial contamination with special emphasis on results from GC-O studies.

Characterization of aroma active compounds in fruit juice and peel oil of Jinchen sweet orange fruit (Citrus sinensis (L.) Osbeck) by GC-MS and GC-O.

Gas chromatography-mass spectrometry (GC-MS) and gas chromatography-olfactometry (GC-O) were used to determine the aromatic composition and aroma active compounds of fruit juice and peel oil of Jinchen sweet orange fruit. Totals of 49 and 32 compounds were identified in fruit juice and peel oil, respectively. GC-O was performed to study the aromatic profile of Jinchen fruit juice and peel oil. A total of 41 components appeared to contribute to the aroma of fruit juice and peel oil. Twelve components were the odorants perceived in both samples. The aromatic compositions of fruit juice were more complex than that of peel oil. Ethyl butanoate, β-myrcene, octanal, linalool, α-pinene, and decanal were found to be responsible for the aromatic notes in fruit juice and peel oil. Nineteen components have been perceived only in the juice and ten compounds were described as aromatic components of only the peel oil by the panelists. These differences lead to the different overall aroma between fruit juice and peel oil.

Identification of Grape Juice Aroma Volatiles and Attractiveness to the Mexican Fruit Fly (Diptera: Tephritidae)

Volatiles from a Concord grape juice produced in Mexico were identified, tested for attractiveness, and mixed into an attractive blend. Volatiles were sampled with solid phase microextraction (SPME). Chemicals were analyzed by gas chromatography and identified by mass spectrometry (GC-MS). Identified chemicals were ethanol, ethyl propionate, ethyl butyrate, ethyl 2-methylbutyrate, ethyl decanoate, ethyl dodecanoate, D-limonene, sorbic acid, benzoic acid, methyl anthranilate, and dimethyl anthranilate. Chemicals were tested at 2 concentrations, 1 μg and 100 ng, for attractiveness to Mexican fruit flies (Anastrepha ludens) in laboratory cage-top bioassays. All test chemicals except sorbic acid were attractive to either sugar-fed or sugar-starved flies over both concentrations tested. A nine-component synthetic grape essence mixture was developed that matched the headspace volatiles profile of the grape juice. Attractiveness of the mixture was equal to that of the grape juice in laboratory bioassays. The mixture was 70% as attractive as the juice in traps in field tests. Results demonstrate that most of the attractive principals of the juice were identified.

Test method for detecting adulterated apple juice using piezoelectric resonators

The adsorption of a mixture of volatile components comprising the aroma of apple juice was studied using piezoelectric quartz microweighing. Conventional gas-chromatographic adsorbents and specific films of different natures were used to modify the electrodes of a piezoelectric sensor. The conditions of the juice analysis were optimized using a piezoelectric sensor array in the batch mode. Different samples of apple juice and nectar were analyzed under the same conditions using the piezoelectric sensor array. The quality of the samples was estimated by comparing kinetic mass aromagrams. A method was developed for the rapid estimation and assortment identification or the detection of the adulteration of natural and reconstituted apple juice.

Aroma Characteristics of Steamed Sweet Potato-Comparison with Apple Juice Aroma Characteristics-

In this study, the aroma characteristics of steamed sweet potato were compared with those of apple juice and the difference was clarified by sensory evaluation and odor sensor and electroencephalographic analyses. Although apple juice aroma was evaluated to be pleasant by all seven subjects, the same tendency was not observed for all the subjects on the electroencephalogram. Three subjects were relaxed by apple juice aroma, however no changes in α1and α2wave power were observed for the remaining four subjects. It was concluded that apple juice aroma elicits no unpleasant mood. On the other hand, by smelling steamed sweet potato aroma, α wave power was markedly decreased and a sense of tension [was enhanced]. A significant difference between apple juice aroma and steamed sweet potato aroma was observed on the basis of the changes in α wave power. It was clarified that steamed sweet potato aroma is different from apple juice aroma, and is not as pleasant as apple juice aroma.

DETERMINATION OF ORTHO‐NASAL AROMA THRESHOLD FOR MULTICOLORED ASIAN LADY BEETLE IN A CONCORD GRAPE JUICE

ABSTRACT Sensory evaluation was used to determine the aroma threshold of Harmonia axyridis (multicolored Asian lady beetle [MALB]) in Concord grape juice. Prior to Concord grape juice preparation, MALB was added to the Concord grapes at concentrations of 0 and 8.4 MALB/kg fresh grapes. To determine the odor threshold, the three alternative forced‐choice method of sample presentation was used, with an ascending concentration series of 0.5, 1.5 and 4.5 MALB/kg fresh grapes. The panel aroma threshold concentration, calculated using the best estimate threshold over two panel sessions, was 1.8 MALB/kg fresh grapes. Individual detection thresholds ranged from 0.29 to 7.79 MALB/kg fresh grapes, with 75% of the panelists having a detection threshold at or below 0.87 MALB/kg fresh grapes. These results indicate the influence of low numbers of MALB on Concord grape juice aroma, and suggest the importance of quality control programs, including the implementation of established tolerance limits, to monitor grape quality.PRACTICAL APPLICATIONS Harmonia axyridis, the multicolored Asian Ladybeetle (MALB), was originally introduced as a method of biocontrol. However, its presence is now becoming problematic with respect to crop quality. In order to minimize economic losses to the Concord grape industry, determination of the number of MALB required to produce a detectable change in Concord grape juice is critical for juice producers in the establishment of their quality control programs. Therefore, the objective of this study was to determine the aroma threshold level of MALB in Concord grape juice. The panel aroma threshold concentration, calculated using the best estimate threshold was 1.8 MALB/kg fresh grapes, with 75% of the panelists having a detection threshold at or below 0.87 MALB/kg fresh grapes. These results indicate the influence of low numbers of MALB on Concord grape juice aroma, and suggest the importance of quality control programs, including the implementation of established tolerance limits, to monitor grape quality.

Recuperação e concentração de componentes do aroma de caju (Anacardium occidentale L.) por pervaporação

Pervaporation is a membrane separation process in which components from liquid mixtures are fractionated due to their partial vaporisation through a dense selective membrane. This process can be used to recover aroma compounds. The objective of this work was to evaluate the pervaporation to obtain a natural aroma extract from cashew apple fruit, which can be used as an additive in the food industry. Cashew pulp was used as raw material. Pervaporation was carried out at 25 and 35 °C using polymethylsiloxane membranes. Samples of the cashew juice in the beginning and at the end of the pervaporation and from the permeate were picked to characterise the aromatic profile by GC-MS. The pervaporation of the cashew juice presented a high permeate flux, 0.11 kgh-1m-2 and 0.17 kg.hm-2, at 25 and 35 °C, respectively. The chromatograms showed an increase in the number of compounds in the permeate samples when compared to the chromatograms of the cashew juice. By comparing the peak areas, it could be observed that almost 50% of the identified components in the permeate samples presented an increase in the peak area, showing the potentiality of this process to the concentration of the aroma of cashew apple juice.

Enhancing the Retention of Phytochemicals and Organoleptic Attributes in Muscadine Grape Juice through a Combined Approach between Dense Phase CO2Processing and Copigmentation

This study evaluated the phytochemical stability and organoleptic attributes of an ascorbic acid-fortified muscadine grape juice as affected by dense phase CO2 processing (DP-CO2) and addition of thyme polyphenolic cofactors (Thymus vulgaris; 1:100 anthocyanin-to-cofactor molar ratio) in efforts to prevent phytochemical losses that occur during storage of anthocyanin-containing beverages, especially in the presence of carbonyl compounds commonly produced during thermal processing and storage. DP-CO2 processing insignificantly altered initial juice phytochemical and antioxidant content, whereas thermal pasteurization reduced anthocyanins (263 mg/L), ascorbic acid (42 mg/L), soluble phenolics (266 mg/L), and antioxidant capacity (6 microM Trolox equivalents/mL). Similar trends were observed during storage, and data showed that increasing the CO2 level from 8 to 16% during DP-CO2 was instrumental in reducing juice phytochemical and antioxidant degradation. Copigmentation was instrumental in retaining higher anthocyanin, soluble phenolics, and antioxidant capacity during storage without affecting initial juice aroma and flavor characteristics. Moreover, on the basis of overall likeability scores, panelists preferred copigmented juices, which had increased juice color intensity and masked the detrimental color fading that occurred during storage, especially when compared to thermally pasteurized juices. DP-CO2 and copigmentation were effective strategies to reduce phytochemical and color deterioration that occurred in muscadine juice during storage without affecting their organoleptic attributes.

Microbial Stability, Phytochemical Retention, and Organoleptic Attributes of Dense Phase CO2 Processed Muscadine Grape Juice

Dense phase CO2 processing (DP-CO2) is a promising alternative to thermal pasteurization potentially inactivating microorganisms without affecting food phytochemicals or organoleptic characteristics. To demonstrate these effects, studies were conducted by changing processing pressure and CO2 concentration in relation to microbial destruction. Subsequent storage stability (10 weeks at 4 degrees C) of muscadine grape juice processed by DP-CO2 (34.5 MPa at 8% or 16% CO2) was evaluated and compared to a heat-pasteurized juice (75 degrees C, 15 s). Thermal pasteurization decreased anthocyanins (16%), soluble phenolics (26%), and antioxidant capacity (10%) whereas no changes were observed for both DP-CO2 juices. DP-CO2 juices also retained higher anthocyanins (335 mg/L), polyphenolics (473 mg/L), and antioxidant capacity (10.9 micromol of Trolox equivalents/mL) than thermally pasteurized juices at the end of storage. Insignificant differences in sensory attributes (color, flavor, aroma, and overall likeability) were observed between unprocessed and DP-CO2 juices, while significant differences were observed between unprocessed and heat-pasteurized juices. Panelists preferred DP-CO2 over heat-pasteurized juices throughout the first 6 weeks of storage, whereby the growth of yeast and mold adversely affected the juice aroma. Comparable microbial counts were observed between DP-CO2 and thermally pasteurized juices during the first 5 weeks of storage. DP-CO2 protected phytochemicals in muscadine juice during processing and storage without compromising microbial stability or sensory attributes over 5 weeks of storage.

Influence of processing parameters and membrane type on permeate flux during solution concentration of different alcohols, esters, and aldehydes by reverse osmosis

Aroma compounds are heat-sensitive and easy volatile components, which are lost with co-vapour during concentration by evaporation. Many authors found out that a loss of volatile aroma compounds was significantly smaller in fruit juice concentration by reverse osmosis than in concentration by evaporation. This work deals with the application of reverse osmosis for solution concentration of alcohols, esters and aldehydes, which are components of apple juice aroma. The influence of the membrane type, processing pressure parameters and shares of alcohols, esters and aldehydes in initial solution was investigated. Effect of the molecular mass and molecule structure on the permeate flux in model solution concentration by reverse osmosis was also observed. Influence of activity and activity coefficient of the mentioned compounds on the permeate flux was studied. Concentration by reverse osmosis was carried out by the instrument “Lab Unit M 20” with the plates and frames of the DDS firm at the temperature of 18°C. Composite membranes of the types HR 95 PP and HR 98 PP (aromatic polyamide membrane HR 95 PP of 95% NaCl rejection and HR 98 PP of 97.5% NaCl rejection), with the total surface of 0.347m2, were applied. Research results showed that the mentioned processing parameters, molecular mass and molecule structure influenced the permeate flux during the model solution concentration. Better permeate flux was achieved in alcohol solution concentration with the membrane type HR 95 PP than with the HR 98 PP membrane. The membrane type HR 98 PP had greater permeability during the model solution concentration of esters and aldehydes.

Concentration of aqua solutions of organic components by reverse osmosis. I: Influence of trans-membrane pressure and membrane type on concentration of different ester and aldehyde solutions by reverse osmosis

Volatile aroma components of fruit juices are lost with vapour during concentration by evaporation. However, these components are mostly retained in fruit juice by membrane processes concentration. Application of reverse osmosis for concentration of ester and aldehyde solutions, being components of apple juice aroma, was investigated. Influence of process pressure, percentages of different esters and aldehydes (0.01% v/v, 0.05% v/v and 0.1% v/v), influence of molecule structure, molecular mass and membrane type on concentration of model solutions of esters and aldehydes by reverse osmosis were studied. Effects of activity and activity coefficient of esters and aldehydes on concentration were investigated too. Research was carried out with model solutions of esters (ethyl acetate, butyl acetate, hexyl acetate, amyl acetate, iso-amyl acetate, iso-amyl propionate, ethyl butyrate, ethyl 2-methyl butyrate) and aldehydes (hexanal, trans-2-hexenal). Reverse osmosis concentration was carried out on laboratory equipment with plates and frames using two types of composite membranes (aromatic polyamide membrane HR 95 PP of 95% NaCl rejection and HR 98 PP of 97.5% NaCl rejection). Aroma components (esters and aldehydes) of the retentate and permeate were determined by gas chromatography with a mass detector (GC/MS) and a “head space” technique. Results of this research showed that ester and aldehyde water solutions of different molecular mass and structure could be concentrated successfully by reverse osmosis. These results also give a better insight into mechanisms of aroma compounds retention (esters, aldehydes) in the retentate, during concentration of water solutions by reverse osmosis. On the membrane HR 98 PP was greater retention of esters: ethyl acetate, butyl acetate, ethyl butyrate and ethyl 2-methyl butyrate than the membrane HR 95 PP. On the membrane HR 95 PP was greater retention of esters: hexyl acetate, amyl acetate, iso-amyl acetate, iso-amyl propionate and aldehydes: hexanal and trans-2-hexenal than the membrane HR 98 PP. Concentration factor was higher in the retentate and OCP (organic components passage) was lower in the permeate when ester and aldehyde portions in the feed solution and molecular mass were greater. Ester concentration of n-structural form showed a greater concentration factor in the retentate and lower OCP (organic components passage) in the permeate. The greater retention in the retentates was realised by aldehyde concentration with a double bond in the molecule. Membrane selectivity and retention of esters and aldehydes was greater in the retentate than in the permeate with application of higher process pressure.

Orange juice concentration by osmotic evaporation and membrane distillation: A comparative study

Abstract In this work, the osmotic evaporation (OE) and membrane distillation (MD) processes were compared in terms of water flux and aroma retention. The concentration of a sucrose solution, used as a model fruit juice, was carried out in a hollow fibre membrane contactor. Although a similar overall driving force was used, the flux obtained using the MD process was less than half of that observed using the OE process, due to temperature polarization effects. The transport of citral and ethyl butyrate, two aroma compounds relevant in the orange juice aroma, was also compared for both processes. A higher retention of these compounds was observed with the OE process. From these studies, it could be concluded that, the OE process has advantages over the MD process, not only in terms of water flux, but also regarding the retention of aroma compounds. Finally, the concentration of a commercial orange juice by osmotic evaporation, was carried out. Due to the presence of suspended solids and macromolecules, a higher mass transfer resistance was observed.

Identification of medicinal off-flavours generated by Alicyclobacillus species in orange juice using GC-olfactometry and GC-MS

The objective of this study was to identify compounds responsible for medicinal off-flavours produced by different species and strains of Alicyclobacillus in orange juice using a combination of chromatographic-coupled olfactometric techniques and gas chromatography-mass spectrometry (GC-MS). Each of five Alicyclobacillus strains was inoculated into separate juice samples and incubated up to 28 days at 45 degrees C. Aroma compounds in the juice were analysed by GC-olfactometry (GC-O) and confirmed using GC-MS. GC-O identified three components that were described as medicinal/antiseptic. Microbial populations were enumerated at timed intervals by spiral plating onto Alicyclobacillus agar. Within 28 days incubation, all five strains produced medicinal off-aromas from guaiacol and at least one halogenated phenol. This is the first study to evaluate individual juice aroma components produced by Alicyclobacillus species using olfactometry and to demonstrate that at least three medicinal off-flavour compounds are associated with the growth of alicyclobacilli in orange juice.

Influence of Thermal Treatment on Black Currant (Ribes nigrumL.) Juice Aroma

The influence of thermal treatment on black currant juice aroma was investigated in temperature and time ranges relevant for black currant juice concentration processes, namely, 45, 60, 75, and 90 degrees C. Forty-nine aroma compounds were quantified, and the thermal treatment resulted in concentration increases of most terpenes, aldehydes, furans, and phenols, whereas the concentration of esters slightly decreased. Higher temperatures and longer exposure times had larger effects on the aroma compounds. Odor triangle tests showed no sensory difference between pasteurized juice and juice heated at 60 degrees C, whereas juice heated at 90 degrees C differed significantly from pasteurized juice. It is concluded that a 90 degrees C thermal treatment of black currant juice, which is in the temperature range used for conventional evaporation of black currant juice, has an effect on the aroma and sensory properties.

Consumer acceptance of orange juice containing functional ingredients

This study examined the sensory impact of functional ingredients (e.g., probiotics, prebiotics, vitamins, and minerals) on the aroma and taste of orange fruit juices. A trained panel ( n =10) performed a descriptive sensory analysis on four functional orange juices and seven conventional orange juices. The functional juices were described as possessing perceptible “dairy”, “medicinal” and “dirty” flavours, distinguishing them from the conventional juices. Subsequently, 100 consumers participated in a preference test, whereby five orange juices (three conventional and two functional) were ranked in order of consumer preference. Ranking decisions were based solely on the sensory characteristics of the juices, since product information was not provided. On an overall basis, consumers preferred the sensory characteristics of conventional juices. However, cluster analysis identified a small consumer segment (11%) that significantly preferred the sensory attributes of functional juices.

Which juice is ‘healthier’? A consumer study of probiotic non-dairy juice drinks

This study evaluated consumer acceptance for the appearance, aroma, texture and flavour of probiotic fruit juices. Novel blackcurrant juices containing probiotic cultures ( Lactobacillus plantarum 299v) were compared with conventional blackcurrant juices by descriptive analysis. The probiotic juices were found to contain aromas (‘perfumey’, ‘dairy’) and flavours (‘sour’, ‘savoury’) characteristic of functional ingredients. Subsequent testing took place in a local shopping centre, where consumers ( n=425) were presented with two randomly coded blackcurrant juice samples. One of the products was a natural blackcurrant juice, and the other was a commercially processed blackcurrant juice containing probiotic cultures. Consumers were instructed that one of the juice samples contained “special ingredients” designed to improve their health. Consumers were asked to assess their overall impression of both juices, and to rate their acceptance of the sensory characteristics of both juices. Furthermore, based on their overall impressions and guided by their individual expectations, consumers were asked to identify the juice they perceived to be the ‘healthiest’ (e.g., containing the “special ingredients”). Juice preference was dependent on gender and age. In general, consumers selected their most preferred juice product as the ‘healthiest’ sample.

Consumer acceptance of orange juice containing functional ingredients

This study examined the sensory impact of functional ingredients (e.g., probiotics, prebiotics, vitamins, and minerals) on the aroma and taste of orange fruit juices. A trained panel ( n=10) performed a descriptive sensory analysis on four functional orange juices and seven conventional orange juices. The functional juices were described as possessing perceptible “dairy”, “medicinal” and “dirty” flavours, distinguishing them from the conventional juices. Subsequently, 100 consumers participated in a preference test, whereby five orange juices (three conventional and two functional) were ranked in order of consumer preference. Ranking decisions were based solely on the sensory characteristics of the juices, since product information was not provided. On an overall basis, consumers preferred the sensory characteristics of conventional juices. However, cluster analysis identified a small consumer segment (11%) that significantly preferred the sensory attributes of functional juices.

Recovery of volatile aroma compounds from black currant juice by vacuum membrane distillation

This study evaluated the recovery of seven characteristic black currant aroma compounds by vacuum membrane distillation (VMD) carried out at low temperatures (10–45 °C) and at varying feed flow rates (100–500 l/h) in a lab scale membrane distillation set up. VMD at feed flow from 100 to 500 l/h at 30 °C gave concentration factors, calculated for each aroma compound as C permeate/ C feed, from ∼4 to 15. The concentration factors increased with decreased juice temperature during VMD; at 10 °C concentration factors of 21–31 were obtained for the highly volatile aroma esters. The recovered levels of the highly volatile aroma compounds ranged from 68 to 83 vol.% with a feed volume reduction of 5 vol.% (10 °C, 400 l/h). The theoretically predicted aroma recovery as a function of the feed volume reduction was in accordance with the experimentally obtained values. VMD thus turned out to be a promising technique for gentle stripping of black currant juice aroma compounds.

Deacidification of clarified passion fruit juice using different configurations of electrodialysis

AbstractThe deacidification of clarified passion fruit juice (P edulis v flavicarpa) was investigated using the electrodialysis process (ED). Different stack configurations like conventional electrodialysis (ED2C), three compartments electrodialysis (ED3C) and electrodialysis with bipolar membranes (EDBM3C, EDBM2C) were tested. The conventional electrodialysis did not allow the deacidification of the clarified juice, whilst with the other configurations the pH of juice was increased from 2.9 (initial value) to 4.0 (target level). The ED performances were evaluated as a function of the nature of the anion exchange membrane (AEM), flow rate and current density. The physico‐chemical and sensorial properties of the deacidified juices were similar : the titrable acidity was reduced from 4.3 to 1.14% w/w, the dry soluble extract varied from 13.2 to 11% w/w, the anion concentration was significantly decreased (60% of organic and 85% of inorganic anions were eliminated), the cation concentration remained inchanged, except for the sodium concentration that increased by using ED3C and EDBM3C configurations. The aroma of the passion fruit juice was preserved after treatment whatever the ED configuration used. The EDBM2C configuration deserves a special attention because the consumption of chemicals is totally eliminated and a valuable solution of citric acid with 89% of purity can be produced. Copyright © 2003 Society of Chemical Industry

Efeito da radiação gama sobre o perfil sensorial de suco de laranja

O trabalho teve como objetivo avaliar o efeito de doses de radiações sobre as características sensoriais do suco fresco de laranja variedade 'Pêra' (Citrus sinensis L) conservado sob refrigeração. Utilizou-se amostras de suco de laranja refrigerado (controle) e suco de laranja refrigerado irradiado com 1,5 e 3,0kGy por hora (Cobalto60), armazenadas a 4ºC por 1, 7, 14 e 21 dias a 4ºC. Para a análise sensorial realizou-se a Análise Descritiva Quantitativa, na qual provadores selecionados e treinados avaliaram a aparência, aroma, sabor e textura oral dos sucos. As doses de radiação alteraram características de aparência como cor, brilho e grumosidade. As amostras de suco irradiados apresentaram coloração amarelo mais claro, maior brilho e menor grumosidade que o suco controle. Os sucos irradiados apresentaram também maior intensidade de aroma cozido, passado e artificial, gosto ácido, amargo, sabor cozido, de sumo, passado e de laranja artificial. As doses de radiação utilizadas alteraram as características de corpo e adstringência. A cor e a grumosidade do suco não irradiado intensificaram-se com o tempo de armazenamento. Com base nos resultados obtidos, pode-se concluir que a irradiação do suco promoveu alterações nas características sensoriais.