Untreated Juice Research Articles

The use of fuzzy logic to determine the concentration of betel leaf essential oil and its potency as a juice preservative

The present study was attempted to determine organoleptically acceptable concentration of betel leaf essential oil (BLEO) in raw apple juice using fuzzy logic approach, and to evaluate the efficacy of the acceptable concentration in the juice under refrigerated storage. The presence of BLEO components in treated juice was confirmed by FTIR spectroscopy. Based on similarity values, the acceptable concentration in the juice was found to be 0.19µl/ml of BLEO. Total antioxidant capacity of untreated juice was found to be 16% less than treated juice at the end of storage. The treated juice exceeded total aerobic plate count of 2 log10 (cfu/ml) on 15th day of storage. Based on safe limits of microbial load, the shelf life of treated juice was extended by 6days as compared to untreated juice under refrigerated storage. BLEO contributes to green consumerism and its application as food preservative will add value to the product.

English

Physico-chemical analyses and sensory evaluation were carried out on commercially and freshly prepared orange juice (100%) in the laboratory and its shelf-life after the storage period of 90 days using various storage methods. At the end of the study, the result showed that the laboratory processed orange juice in terms of the nutritional composition when compared with the commercially processed orange juice had a better quality considering the parameters assessed. The results of the laboratory prepared orange juice showed that the chemically treated, pasteurized, concentrated and carbonated orange juice had pH 1.6 to 4.5, TTA 0.03 to 0.31%, maturity ratio 1.16 to 8.55, total soluble solids (TSS) ranging from 26 to 33°Brix. The vitamin C content for the untreated juice (fresh) and the commercially produced were 43 and 2.67 mg/100 ml, respectively. The experimental samples of chemically treated, pasteurized, concentrated and carbonated had vitamin C content ranging from 22-29, 27-32, 28-30 and 17-29 mg/100 ml, respectively. Sodium and phosphorus were found in small amounts ranging from 0.01-0.12 and 0.001-0.02%, respectively in the orange juice. Among the various processing methods concentrated orange juice ranked first followed by chemically treated, pasteurized and carbonated in terms of the sensory evaluation as assessed by the panelists. Key words: Orange juice, physico-chemical properties, processing techniques, sensory evaluation.

Combined Use of Ultrasound and Vanillin to Improve Quality Parameters and Safety of Strawberry Juice Enriched with Prebiotic Fibers

In this work, a previously optimized preservation treatment (vanillin = 1.25 mg/mL; ultrasound = 7.5 min, 40 kHz, 180 W) was applied to strawberry juice enriched with inulin and oligofructose. The evolution of microbial, nutritional, and sensory parameters of treated juices was studied. It was confirmed that the inclusion of inulin and oligofructose had no negative implication regarding the quality of fresh juice. Furthermore, the prebiotic addition maintained sensory attributes of the product. The applied preservation treatment improved almost every quality attribute during storage, reducing microbial development, especially lactic acid bacteria and yeast and mold growth, which rapidly grew in untreated juices. Nutritional quality was also improved by the treatment as total polyphenol and total flavonoid content were increased and ascorbic acid content losses were reduced during storage, indicating higher antioxidant capacity. Overall, the evaluated sensory attributes of treated juices were deemed acceptable (>2.5). The addition of vanillin imparted pleasant flavor notes to the juice, compatible with the fruit product. Also, the performance of the treated juice was evaluated against postharvest contaminations with pathogens of interest in the food industry and of health concern (Escherichia coli O157:H7 and Listeria monocytogenes, evaluated through the surrogate Listeria innocua). The optimized treatment was able to reduce the counts of these microorganisms during storage reaching undetectable values after 7 days of storage. Thus, the combination of vanillin and ultrasound could be a feasible alternative to ensure safety and improve quality parameters of strawberry juice enriched with prebiotic fibers.

Optimisation of minimal processing variables to preserve the functional quality and colour of carrot juice by means of the response surface methodology

SummaryCombined processes based on acidification (pH: 4.5, 5.0, 5.5) and mild thermal treatments (T: 56, 58, 60°C) at different exposure times (t: 2, 4, 6 min) were optimised using the response surface methodology to improve the functional quality of carrot juice. The effects on α‐ and β‐carotenes, total antioxidant activity (TAA) and colour parameters were assessed. All combinations exhibited higher α‐ and β‐carotenes than untreated juice due to an increase on the extractability during processing. T was the most influential factor increasing carotenes as T increased. Conversely, TAA was more affected by pH. The maximum TAA was observed at pH 4.5 at 56°C. Moreover, samples with the lowest pH were the most luminous with highest a* and b*. The combination of pH 4.5 at 60°C, 4 min simultaneously showed high carotenes and TAA, resulting a good alternative to improve the functional quality and colour of carrot juice.

Fermentative production of guava wine from pectinase treated and untreated juice of ‘punjab pink’ cultivar of Psidium guajava L.

A study was conducted to produce wine from juice of guava (Psidium guajava L.) cv. Punjab Pink following treatment with pectinase enzyme. It was observed that pre-fermentative treatment of ‘must’ with 0.50 mg/100ml pectinase at 45°C for 6h resulted in 47.2% clarity of guava juice. Ethanolic fermentation of both pectinase treated and untreated guava juice was optimized at 25°Brix, 25°C with 9% (v/v) inoculum size of Saccharomyces cerevisiae MTCC 11815 and 0.3% (w/v) DAHP supplementation under laboratory conditions. Ethanolic fermentation of treated guava ‘must’ resulted in 13.2 + 0.15% (v/v) ethanol production in 8 days with an ethanol yield of 0.492g/g, while untreated juice resulted in 13.0 + 0.04% (v/v) ethanol production with an ethanol yield of 0.487 g/g. Sensory analysis of guava-wine revealed that wine prepared from untreated guava ‘must’ was of standard quality as compared to superior quality of wine prepared from treated one at 30 days of storage. However, both wines were superior as reflected by sensory scores of 68.1 ± 1.22 and 70.3 ± 1.22, respectively, at 90 days of storage.

Effect of Combining Ultrasound and Mild Heat Treatment on Physicochemical, Nutritional Quality and Microbiological Properties of Pineapple Juice

Increasing consumer awareness regarding the health benefits of different nutrients in food has led to the requirement of assessing the effect of food processing approaches on the quality attributes. The present work focuses on understanding the effects of ultrasound (US) processing, mild heat pasteurization (65°C for 15 min), thermal pasteurization (80°C for 15 min) and their combination on physicochemical, microbiological properties and nutritional quality of pineapple juice through 60 days of storage at room temperature. Ultrasound treatment showed significantly lower browning degree. Ultrasound followed by ultrasound combined with mild heat pasteurization (UMP) treatments was effective in retaining the total phenolic content of pineapple juice as compared to the thermal treatment or the untreated juice sample at room temperature during 60 days of storage. Thermal pasteurization (TP) followed by ultrasound combined with mild heat pasteurization (UMP) and ultrasound (US) treatment, in increasing order, was found to be effective in delaying microbial growth in pineapple juice. This study demonstrates that ultrasound combined with mild heat pasteurization treatments could be able to effectively inactivate the microorganisms and pectin methylesterase in pineapple juice whilst preserving relatively high amount of phenols.

Antioxidant capacity, phenolic composition and microbial stability of aronia juice subjected to high hydrostatic pressure processing

Abstract The aim of this study was to characterize the effect of high hydrostatic pressure (200–600 MPa/15 min) and storage (4 °C/80 days) on aronia juice quality. The total antioxidant capacity, phenolic content and composition were assessed using an updated analytical strategy. Microbial growth was also analyzed following juice storage. Among all the analyzed juices, the untreated aronia juice had the greatest reduction (36%) in total polyphenols over the entire storage period. At the end of the storage period, the pressurized juices demonstrated ABTS and FRAP values higher by 14% and 5% as compared to the untreated juices. The main antioxidants identified in the aronia juice were: chlorogenic acid; neochlorogenic acid; cyanidin 3-galactoside; cyanidin 3-xyloside; cyanidin 3-arabinoside; cyanidin 3-glucoside. Cyanidin 3-glucoside was the most stable compound during juice storage. Microorganism growth in juices pressurized at 400–600 MPa was below the detection limit ( − 1 ) upon storage. Industrial relevance Aronia berries are rarely consumed fresh since they give off several negative sensory attributes. Multiple health-promoting properties of aronia berries make them a valuable raw material for juice production. However, processing involves pasteurization or hot-filling strongly diminishes the product quality due to the changes in quantity and quality of thermolabile phytochemicals. The objective of this work was to characterize the effect of high hydrostatic pressure on the antioxidant capacity, polyphenol content and composition and microbial stability of aronia juice. Results of this study may be useful for the juice industry commercialize this technology for the development healthy, nonclarified aronia juices with desired level of quality.

Effect of Thermoultrasound on the Antioxidant Compounds and Fatty Acid Profile of Blackberry (Rubus fruticosus spp.) Juice.

Blackberry (Rubus fruticosus spp.) fruit has high antioxidant activity due to its significant content of anthocyanins and antioxidant compounds. Among emerging technologies for food preservation, thermoultrasound is a technique that reduces microbial loads and releases compounds with antioxidant properties. The objective of this study was to determine the antioxidant content and fatty acid profile of blackberry juice subjected to thermoultrasound treatment in comparison to pasteurized juice. Blackberry juice and n-hexane extracts from a control (untreated juice), pasteurized, and thermoultrasonicated samples were evaluated for antioxidant activity, fatty acid profile, and antioxidant content. The juice treated with thermoultrasound exhibited significantly (p < 0.05) higher levels of total phenols (1011 mg GAE/L), anthocyanins (118 mg Cy-3-GlE/L); antioxidant activity by ABTS (44 mg VCEAC/L) and DPPH (2665 µmol TE/L) in comparison to the control and pasteurized samples. Oil extract from thermoultrasound juice also had the highest antioxidant activity (177.5 mg VCEAC/L and 1802.6 µmol TE/L). The fatty acid profile of the n-hexane extracts showed the presence of myristic, linolenic, stearic, oleic, and linoleic acids and was not affected by the treatments except for stearic acid, whose amount was particularly higher in the control. Our results demonstrated that thermoultrasound can be an alternative technology to pasteurization that maintains and releases antioxidant compounds and preserves the fatty acids of fruit juice.

Quality comparison of elephant apple juices after high-pressure processing and thermal treatment.

In the present work, the effect of high pressure processing (HPP) on the quality parameters (pH, °Brix, total acidity, viscosity, colour, antioxidant activity, total phenols, total flavonoids, microbial flora, and sensory analysis) of elephant apple (Dillenia indica) juice was investigated. The juice samples were analysed periodically (0, 1, 2, 5, 10, 20, 30, 40, 50 and 60 days) during 60 days of storage period and results were compared with thermally processed as well as with untreated (fresh juice) samples. Slight variations had been observed in the quality parameters like pH, °Brix and total acidity. Other parameters like colour values, antioxidant activity, total phenols and total flavonoids were varied significantly (P < 0.05) in between the treated (HPP and thermal) and untreated juice samples. The microbial counts of the HPP treated samples were lower than the other samples. Sensory results also showed similar results to those of the other analyses that the treated samples were better for consumption rather than the untreated samples. The shelf-life of the HPP processed elephant apple juice was established as 60 days at 4 °C. This study showed that application of HPP effectively maintained quality attributes and extended shelf life of the elephant apple juice. It may be suggested that application of HPP could be considered for commercial application during storage and marketing. © 2016 Society of Chemical Industry.

Impact of High-Intensity Pulsed Electric Fields or Thermal Treatment on the Quality Attributes of Date Juice through Storage

The effects of high-intensity pulsed electric fields (HIPEF) processing (35 kV/cm for 1,000 ms using pulses of 4 ms pulses at 100 Hz in bipolar mode) or thermal treatment (90C for 60 s) on total phenols composition, color parameters, 5- (Hydroxymethyl)furfural (HMF), pH, soluble solids and turbidity were assessed in date juice for five weeks under refrigeration storage (4–5C), having as reference the untreated date juice. After processing, HIPEF treated date juice exhibited lower HMF concentration than pasteurized one. HIPEF treatment did not affect color parameters with respect to other date juices after treatments. Turbidity, soluble solids and pH were more preserved in HIPEF treated date juice compared to heated one after processing and along storage. The content of total phenols increased after HIPEF compared to untreated juice. The HIPEF contributed to the maintain of quality attributes of date juice along refrigeration storage. This process was much better than heat.

Stability of polyphenols in chokeberry juice treated with gas phase plasma

Chokeberry juice was subjected to cold atmospheric gas phase plasma and changes in hydroxycinnamic acids, flavonols and anthocyanins were monitored. Plasma treatments were carried out under different treatment times and juice volumes under constant gas flow (0.75dm3min−1). The results were compared against control (untreated) and pasteurized chokeberry juice (80°C/2min). During pasteurization, the most unstable were hydroxycinnamic acids with losses of up to 59%, while flavonols and anthocyanins increased by 5% and 9%, respectively. On the contrary, plasma treated chokeberry juice showed higher concentrations of hydroxycinnamic acids and 23% loss of anthocyanins in comparison to untreated juice. In order to obtain the optimal cold plasma treatment parameters principal component and sensitivity analysis were used. Such parameters can be potentially used for pasteurization in terms of phenolic stability of chokeberry juice. Optimal treatment was at 4.1min and sample volume of 3cm3.

High pressure processing pretreatment enhanced the thermosonication inactivation of Alicyclobacillus acidoterrestris spores in orange juice

The spoilage of high acid fruit juices and nectars by Alicyclobacillus acidoterrestris is a major concern to juice manufacturers around the world since it is difficult to detect. In this study, thermosonication (ultrasound and heat, TS) and thermal inactivation of A. acidoterrestris spores in pretreated orange juice were carried out and resistance parameters were estimated. First, the effect of TS acoustic energy density (AED, 0.3–20.2 W/mL) on the inactivation at 75 °C was investigated. Then, the influence of TS temperature (70–78 °C) on the spore inactivation (AED = 20.2 W/mL) was studied. Next, we explored the effect of high pressure processing (HPP) pretreatment of juice on the 20.2 W/mL TS inactivation at the best temperature (78 °C). Lastly, the thermal inactivation of spores in juice heat shocked + 1 min sonicated vs. untreated juice was also investigated.Results of TS showed higher spore inactivation for higher AED (D75°C-value of 49 min for 20.2 W/mL vs. 217 min for 0.33 W/mL). Lower D-values were obtained at higher temperatures (D78°C-value of 28 min vs. D70°C-value of 139 min at 20.2 W/mL). The TS D78°C-value (at 20.2 W/mL) decreased further from 28 min to 14 min when the orange juice was previously submitted to 600 MPa for 15 min. Thermal treatment alone at 78 °C resulted in almost no spore inactivation, whereas the heat shock + ultrasound pretreatment of juice enhanced the thermal inactivation of spores (D85°C-value decreased from 69 to 29 min). To conclude, HPP-assisted TS provided the best method for spore inactivation, indicating the benefit of high pressure and power ultrasound technology in addition to heat. TS required at least 8 °C lower temperatures than thermal treatments to achieve the same spore inactivation, which could enhance juice quality and energy savings.

유동 초고압 공정을 이용한 오렌지 주스의 보존성 향상

Effects of dynamic high-pressure (DHP) treatments with and without integration with heating on microbial stability, vitamin C concentration, color, sugar content, and pH of orange juice were studied and compared with those of the conventional thermal treatment. Freshly squeezed orange juice was heated at 90°C for 1 min or DHP-treated at 205 MPa and 20, 50, 60, or 70°C. The DHP treatment at 20°C without heating and the treatment at 50°C inactivated indigenous mesophilic aerobic microorganisms in orange juice by 4.2 and &gt;7 log CFU/mL, respectively. The DHPtreated juice exhibited brighter color and higher vitamin C concentration and sugar content than the thermally treated juice, regardless of integration with heating. The DHP-treated juice demonstrated brighter color and higher sugar contents than untreated juice and thermally treated juice during storage at 4°C for 63 days. The results have demonstrated the potential of applying DHP treatments to pasteurize orange juice with increasing brightness and sugar content of the juice.

Novel biopreservatives to enhance the safety and quality of strawberry juice.

Pomegranate extract, vanillin and geraniol were studied as natural antimicrobials on strawberry juice. Strawberry juice was treated with each agent at two concentrations: pomegranate extract at 180 and 360μg/mL; vanillin at 2.5 and 5mg/mL; and geraniol at 0.6 and 1.2μL/mL. After being treated, juices were stored at 5°C and microbiological, physicochemical and sensory studies were carried out. Also, a second batch of juice was inoculated with Escherichia coli O157:H7 (10(5) CFU/mL) before being treated, to safety study. Geraniol and vanillin, at both concentrations tested, were highly effective in reducing the native microflora on strawberry juice (more than 3 log cycles), extending the microbiological shelf-life of the product. Moreover, both antimicrobials improved the product safety by reducing inoculated E. coli O157:H7. Furthermore, vanillin showed a significant increase in polyphenol content compared to untreated juice. On the other hand, pomegranate extract applied at the highest concentration showed important reductions on mesophilic and psychrophilic bacteria, but no effect on yeast and molds and inoculated E. coli. Even though vanillin and geraniol incorporation on strawberry juice had a negative effect on its sensory quality, pomegranate extract had no impact on the sensory attributes evaluated. Combinations of the biopreservatives could be studied in order to decrease the concentration of the antimicrobials, reducing the effects on strawberry juice sensory characteristics.

The Role of Unsaturated Gaseous Hydrocarbons in Minimization of Sucrose Loses

The activities of acetylene and ethylene for conservation of sucrose contents of crude sugar and lowering the activity of polyphenol oxidase in sugarcane juice were investigated carrying out separate experiments. Results were compared with the crude sugar produced from an untreated juice and that produced from sulfur dioxide-treated juice, an effective deactivator of the polyphenol oxidase. The sucrose contents of all the samples were determined in terms of the pol% and the change in activity of the polyphenol oxidase was determined in terms of the color intensity of each of the crude sugar sample. The causes of these activities have been discussed in this communication. Practical Applications Acetylene and ethylene gases have been used instead of coloring additives (commonly bleaching powder) for the conservation of sucrose contents in the crude sugar. The bleaching powder has various side effects in terms of depleting quality of the sugar and decreasing the shelf life of the sugar. Thus, the bleaching powder and other coloring agents have been replaced with the acetylene and ethylene gases in the present research work which are blocking the activity of polyphenol oxidase enzyme in the sugarcane juice.

Effects of Thermal and Non-thermal Processing on Phenolic Compounds, Antioxidant Activity and Sensory Attributes of Chokanan Mango (Mangifera indica L.) Juice

The increasing demand for fresh-like food products have spurred the development of non-thermal processing such as sonication and ultraviolet-c (UV-C) light treatment. In this study, freshly squeezed Chokanan mango juice was subjected to thermal treatment (at 90 °C for 30 and 60 s), sonication (for 15, 30 and 60 min at 25 °C, 40-kHz frequency) and UV-C treatment (for 15, 30 and 60 min at 25 °C). In addition, combination of sonication and UV-C treatment in a hurdle concept was also conducted. The effects of thermal and non-thermal treatments on phenolic compounds, antioxidant activity and sensory attributes were evaluated and compared with untreated juice (control) for 5 weeks under refrigerated storage (4 ± 1 °C). The results showed better retention of individual phenolic compounds in non-thermal-treated juice, when compared to the control and thermally treated juice. A significant enhancement in antioxidant activities were observed after non-thermal treatment. The sensory evaluation verified that non-thermal-treated juice was preferred more than thermally treated juice. The results obtained support the use of non-thermal treatments (ultrasound and UV-C) for better retention of quality and prolonged shelf life in Chokanan mango juice processing.

Understanding the effect of novel approaches based on ultrasound on sensory profile of orange juice

The present work investigates the effects of novel non thermal processing based on ultrasound on the sensory profile of orange juice and also compares the observed trends with the conventional thermal pasteurization. A novel treatment methodology based on combination of ultrasound and UV irradiations was investigated. The juice quality was assessed in terms of standard parameters (taste, flavor, odor, mouth feel etc.) by panel tests. Physicochemical analysis in terms of color of processed juice (which is an important physical attribute) and oxidation reduction potential (a good indicator of the quantum of oxidants present in the fruit juices) has also been performed. Thermally treated juices had significantly different characteristics that were not very appealing as compared to the ultrasound treated juices or those treated using the combined approach. The sensory properties of the ultrasound treated juices showed that the samples were most acceptable to the consumers and rated at par with the quality parameters of the fresh untreated juices. Overall the present work is the first to report and conclusively establish the usefulness of ultrasound based treatment approaches for maintaining the sensory profile in comparison with the thermally processed juice.

Effect of incorporating alum in cane juice clarification efficiency and sucrose losses

The effect of incorporating alum in the clarification stage of raw juice in sugarcane processing on the juice quality and sucrose loss was investigated. Alum was incorporated in both intermediate and hot liming clarification processes of cane juicing. One portion of the cane juice was used for With Pre-treatment Treatment (WPT) while the other portion constituted No Pre-treatment (NPT) juice. Alum at levels of 0 mg L-1, 50 mg L-1, 100 mg L-1 and 150 mg L-1 was incorporated in both intermediate and hot liming clarification processes in each of the two cane juice portions. Sugar concentration (sucrose, glucose and fructose), oBrix, pH, colour, settling performance (initial settling rates (ISR), final mud volume (MV∞), and turbidity) and residual aluminium ion concentration were evaluated. Any significant variations (p &lt; 0.05) in these parameters were assessed. The study found significantly lower (p &lt; 0.05) sucrose losses in clarified juice from intermediate liming of WPT after alum treatment than in the rest of the clarified juices. Colour and turbidity in the pre-treated cane juice of intermediate liming was reduced by 36.9% and 98.1%, respectively at 150 mg L-1 alum level. An initial settling rate of 260 mL min-1 in WPT cane juice of intermediate liming at 150 mg L-1 alum level resulted in the most compact final mud volume of 10.3%. The residual aluminium concentration (0.025 to 0.048 mg L-1) in alum treated clarified juices was lower than the natural aluminium concentration (0.088 mg L-1) in untreated cane juice. This study showed the potential for the use of alum in cane juice clarification to improve on clarification efficiency and lower sucrose loss.

Electrodialytic removal of nitrate from pineapple juice: effect on selected physicochemical properties, amino acids, and aroma components of the juice.

This study aimed at investigating the effect of nitrate removal from pineapple juice by electrodialysis (ED) on selected properties of the ED-treated juice. Single-strength pineapple juice with reduced pulp content was treated by ED to reduce the nitrate concentration to 15, 10, or 5 ppm. After ED, the removed pulp was added to the ED-treated juice and its properties, including electrical conductivity, acidity, pH, total soluble solids (TSS), color, amino acids, and selected aroma compounds, were determined and compared with those of the untreated juice. ED could reduce the nitrate content of 1 L of pineapple juice from an initial value of 50 ppm to less than 5 ppm within 30 min. A significant decrease in the electrical conductivity, acidity, pH, TSS, and yellowness, but a significant increase in the lightness, of the juice was observed upon ED. Concentrations of almost all amino acids of the ED-treated juice significantly decreased. The concentrations of 8 major compound contributors to the pineapple aroma also significantly decreased. Adding the pulp back to the ED-treated juice increased the amino acids concentrations; however, it led to a significant decrease in the concentrations of the aroma compounds.

Stabilization of Sweet Sorghum Juice for Long-Term Storage

<abstract><title><italic>Abstract.</italic></title> Sweet sorghum is considered a promising alternative feedstock for ethanol production in the U.S. Southeast and Midwest. The most challenging issue in using sweet sorghum as a feedstock is the long-term storage of sweet sorghum juice for year-round supply of the fuel ethanol industry. As much as 20% of its fermentable sugars can be lost in three days after harvest due to bacterial activity. The purpose of this research was to evaluate some novel treatments to stabilize sweet sorghum juice for long-term storage. Sweet sorghum juice was homogenized at 32 kpsi and treated with ozone gas, and storage stability was evaluated by monitoring the chemical composition (fermentable sugar profile, organic acids, and ethanol contents) and microbial characteristics (total aerobic count and lactic bacterial count) of the treated juices stored at room temperature. Results from this research showed that high-pressure homogenizing and ozone treatment could significantly reduce both aerobic bacterial counts and lactic acid bacterial counts (2.5 log reduction in ABC and more than 3 log reduction in LAB) as evaluated using 3M Petrifilm. After storage for three months at room temperature, the microbial counts of the treated juice remained ~3 log lower than those in the untreated juices. The untreated juice became thick and sticky, and its sugar profile changed significantly, retaining only around 30% of its original content. Although the sugar profiles of high-pressure homogenized juices changed, they retained 80% to 92% of their original sugar contents.