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1.
Begoa de Ancos Sonia Sgroppo Lucía Plaza M Pilar Cano 《Journal of the science of food and agriculture》2002,82(8):790-796
Effects of high‐pressure treatment on the orange juice carotenoids (β‐carotene, α‐carotene, zeaxanthin, lutein and β‐cryptoxanthin) associated with nutritional (vitamin A) and health‐related (radical‐scavenging capacity) values were investigated. Various high‐pressure treatments (50–350 MPa) combined with different temperatures (30 and 60 °C) and times (2.5, 5 and 15 min) of treatment were assayed. The carotenoid content of the orange juice was analysed by HPLC‐UV, the vitamin A value was determined as retinol equivalents (RE) and the free radical‐scavenging capacity was evaluated using the DPPH (2,2‐diphenyl‐1,1‐picrylhydrazyl) radical model system. A storage study was carried out at refrigeration temperature (4 °C). High‐pressure treatments at 350 MPa produced significant increases of 20–43% in the carotenoid content of fresh orange juice (from 3.99 to 4.78–5.70 mg l?1). A non‐uniform behaviour of high‐pressure treatments was detected. An increase in time (beyond 5 min) or temperature (above 30 °C) of treatment did not improve the amount of carotenoids extracted. Owing to better extraction of carotenoids, an increase in vitamin A value from 164 to 238 RE l?1 (45%) was achieved with the 350 MPa/30 °C/5 min treatment. No correlation was found between the increase in carotenoid amount extracted and the free radical‐scavenging activity. © 2002 Society of Chemical Industry 相似文献
2.
Lucía Plaza Concepción Sánchez-Moreno Pedro Elez-Martínez Begoña de Ancos Olga Martín-Belloso M. Pilar Cano 《European Food Research and Technology》2006,223(4):487-493
A better knowledge of the effect of refrigerated storage on the nutritional and antioxidant characteristics of foods processed by emerging technologies with regard to thermal traditional technology is necessary. Thus, freshly squeezed orange juice was processed by high-pressure (HP) (400 MPa/40 °C/1 min), pulsed electric fields (PEF) (35 kV/cm/750 μs) and low pasteurization (LPT) (70 °C/30 s). The stability of vitamin C and antioxidant activity was studied just after treatment and during 40 days of refrigerated storage at 4 °C. The determination of total vitamin C (ascorbic acid plus dehydroascorbic acid) was achieved by HPLC whereas the antioxidant activity was assessed by the measurement of the DPPH• radical scavenging. Just after treatment, all treated orange juices showed a decrease lower than 8% in vitamin C content compared with the untreated one. At the end of refrigerated storage, HP and LPT juices showed similar vitamin C losses (14 and 18%, respectively) in relation to untreated juice, although HP juices maintained better the vitamin C content during more days than LPT juices. Regarding antioxidant activity, after 40 days at 4 °C, differences among treated juices were no significant in terms of antiradical efficiency (AE=1/EC50TEC50). HP and PEF may be technologies as effective as LPT to retain antioxidant characteristics of orange juice during refrigerated storage. 相似文献
3.
The impact of different processing technologies, including non-thermal technologies, on bioactive compounds of orange juice was investigated. Freshly squeezed orange juice was treated by high pressure (HP) (400 MPa/40 °C/1 min), pulsed electric fields (PEF) (35 kV cm−1/750 μs) and low pasteurization (LPT) (70 °C/30 s). The stability of main carotenoids and flavanones was studied just after treatment and during 40 days of refrigerated storage at 4 °C. Just after treatment, HP juice showed a significant increase on total carotenoid and flavanone content extracted (45.19 and 15.46%, respectively) and on vitamin A value (30.89%) with regard untreated juice, whereas no significant changes were observed for PEF and LPT juices. For all treated orange juices, flavanone content decreased significantly (around 50%) during the first 20 days of storage at 4 °C while carotenoid content showed a moderate decrease (less than 11%) that took place during the last 20 days. In general, during refrigerated storage, carotenoids and flavanones remained higher in HP juice than in LPT and PEF juices. Hence, HP and PEF technologies were as effective o even more than LPT to preserve bioactive compounds in orange juice during refrigerated storage. 相似文献
4.
Hye Kyung Kim Kang-Hyun Leem Sena Lee Byung-Young Kim Young Tae Hahm Hyung-Yong Cho Jeung Yun Lee 《Food science and biotechnology》2012,21(1):175-181
Present study investigated the effects of high hydrostatic pressure treatment (HHP, 500 MPa/3 min/ 25°C) on bioactive compound
as well as antioxidant, immunomodulatory potentials, and microbial safety of cloudy juice from ‘Fuji’ apples. HHP did not
cause any significant changes in vitamin C content whereas total polyphenol content was increased. The antioxidant potentials
measured by DPPH and nitric oxide (NO) radical scavenging tests were preserved by HHP, while thermal treatment reduced antioxidant
potentials. NO scavenging activity was greater than DPPH scavenging activity. The immunomodulatory effect assessed by splenocyte
proliferation was increased in a dose-dependent manner, and HHP preserved immunomodulatory activity of apple juice. Furthermore,
HHP treated juice was microbiologically safe without any physicochemical changes during 21 days of storage at 4°C. These results
demonstrated the efficacy of HHP for preserving both nutritional and immunomodulatory functional characteristics of apple
juice, and alternative method for preserving as freshly squeezed for up to 21 days. 相似文献
5.
The effect of high-intensity pulsed electric field (HIPEF) processing parameters (electric field strength, treatment time, and polarity) on broccoli juice carotenoids, vitamin C, total phenolic (TP) content and antioxidant capacity (AC) was evaluated. Results obtained from HIPEF-processed broccoli juice were compared with those of thermally treated (90 °C/60 s) and untreated juices. HIPEF processing parameters influenced the relative content (RC) of bioactive compounds, and the relative AC (RAC). Maximum RC of lutein (121.2%), β-carotene (130.5%), TP (96.1%), vitamin C (90.1%) and RAC (5.9%) was reached between 25 and 35 kV/cm and from 2000 μs to 500 μs. The highest RAC and RC of bioactive compounds were observed in HIPEF treatments applied in bipolar mode, except for vitamin C. HIPEF-treated broccoli juice exhibited greater RC of bioactive compounds and RAC than juice treated by heat. HIPEF technology could be considered a promising option for preserving the antioxidant quality of broccoli juice.Industrial relevanceVegetable juices are becoming more and more popular because of their wide range of health-related compounds. Particularly, broccoli juice is attracting the food industry attention because it contains high amounts of vitamins, carotenoids and phenolic compounds, among other bioactive compounds. Broccoli juice requires treatment conditions that protect its microbial, nutritional and sensorial quality. HIPEF is a non-thermal technology for liquid food preservation that inactivates microorganisms and enzymes without compromising the nutritional and sensorial features of foods. Consequently, this technology could be used in the food industry as an alternative for thermal treatment to preserve the bioactive compounds present in vegetable juices, offering to consumers a healthy product. 相似文献
6.
Huawei Zeng Yuying Shuai Xin Zeng Bingyue Xin Mingqua Huang Bin Li Jie Qiao Yijia Wang Xiaoli Qiu Chengtao Wang 《International Journal of Food Science & Technology》2021,56(2):648-660
This study identified and compared the health-related components and bioactivity of five fruit juices following Lactobacillus plantarum NRRL-B-14768 fermentation and subsequent simulated gastrointestinal digestion. After 48-h fermentation, the vitamin C and total phenol content of orange juice, the polysaccharide content of watermelon juice and the content of functional elements in orange and tomato juices were relatively high. FTIR spectroscopy was used to reveal changes in phenols and organic acids. During fermentation, orange juice displayed the best 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) free radical scavenging capacities and inhibition of α-glucosidase (α-GC) and xanthine oxidase (XO), compared to the other fruit juices. After simulated gastrointestinal digestion, fermented orange juice had the highest vitamin C content, DPPH and ABTS free radical scavenging capacities and XO inhibitory activity, and fermented pineapple juice had the highest α-GC inhibitory activity. These results indicated the potential of these juices in producing fermented juice with high specific functionality. 相似文献
7.
Industrial orange juice debittering: Impact on bioactive compounds and nutritional value 总被引:2,自引:0,他引:2
Carla M. Stinco Rocío Fernández-Vázquez Dolores Hernanz Francisco J. Heredia Antonio J. Meléndez-Martínez Isabel M. Vicario 《Journal of food engineering》2013
The impact of an industrial debittering process (DP) on nutritional and bioactive compounds in orange juice (OJ) was studied. The DP was aimed at removing bitter components in OJ by physical adsorption in a resin. The levels of bioactive compounds (carotenoids, ascorbic acid and phenolics), total antioxidant activity and the colour in the fresh orange juices (non-debittered) and in the debittered counterparts were measured. The results demonstrated that the carotenoid contents were not significantly affected by the treatment. However, the debittered orange juices showed a reduction (p < 0.001) of 26% in ascorbic acid, 32% in hydroxycinnamic acids, 28% of flavones and 41% of flavanones in comparison with the non-treated juices. The antioxidant activity of the hydrophilic fraction (HF) was significantly higher (p < 0.05) in untreated juice than in debittered juices. Some colour parameters (L∗, a∗ and hab) were also affected. Discriminant analysis revealed that the canonical function related to the levels of HF compounds allowed a 100% correct classifications of the different types of juices. 相似文献
8.
Patricia Navarro Antonio Jesus Melendez‐Martinez Francisco Heredia Jose Antonio Gabaldon Ángel Antonio Carbonell‐Barrachina Antonio Soler Antonio José Perez‐Lopez 《International Journal of Food Science & Technology》2011,46(10):2182-2190
The effects of organic farming, pasteurisation and addition of β‐cyclodextrin on the content of vitamin C, colour, carotenoids and antioxidant capacity of orange juices were studied. After pasteurisation at 98 °C (20 s) and subsequently storage along 145 days at room temperature (20–25 °C), the loss of vitamin C content was around 30%. The effects of the thermal process on carotenoid were clearly observed in lutein (loss of 16% for organic and traditional 8%) and especially β‐cryptoxanthin (loss of 30%). The colour changes were noticeable after the pasteurisation of orange juice and subsequent storage, with significant decreases being observed in lightness and the coordinate a*, while increases were found for coordinates b*, Hue* and chroma. The antioxidant capacity was 0.075 ± 0.01 and 0.053 ± 0.01 mMT mL?1 for organic and conventional, respectively, with losses around 40% being found at the end of the storage period. The addition of β‐cyclodextrin caused no significant effects on the parameters under analysis. These data showed that strong thermal treatments, such as pasteurisation, adversely affect the nutritional and sensory quality of orange juices. 相似文献
9.
Antonio J. Meléndez-Martínez Isabel M. VicarioFrancisco J. Heredia 《Food chemistry》2007,101(1):177-184
The vitamin C and provitamin A carotenoids contents of 25 commercially available Spanish orange juices were studied. Large differences in the levels of these compounds were found. On average, ultrafrozen orange juices (UFOJ) and orange juices from the ecological agriculture (OJFEA) showed the highest ascorbic acid contents (518 and 412 mg/l respectively) among the different kinds of orange juices studied. Some disagreement between the declared and the actual amounts of vitamin C were found. Provitamin A carotenoids were determined by means of the corresponding standards. The monohydroxycarotenoid accompanying β-cyptoxanthin in orange juices was identified as the non-provitamin A carotenoid, zeinoxanthin, on the basis of the methylation test with acidified methanol. Unusually high contents of β-carotene (>0.5 mg/l) were found in two samples, which could indicate that substantial amounts of the pigment were added to those juices. The mandarin juice analyzed showed the highest provitamin A activity (359.3 retinol activity equivalents/l) Among the orange juices surveyed, UFO proved to be the best source of provitamin A (78.5 retinol activity equivalents/l, on average). The lowest contents were found in orange juices from concentrate (OJFC) (22.4 retinol activity equivalents/l, on average, without considering the orange juices with unusual β-carotene contents). 相似文献
10.
Julian K. Aschoff Katja Knoblauch Christian Hüttner Ana Lucía Vásquez-Caicedo Reinhold Carle Ralf M. Schweiggert 《Food and Bioprocess Technology》2016,9(10):1681-1691
Non-thermal pasteurization of orange juices using a continuous pressure change technology (PCT) device was investigated on pilot plant scale for the first time. PCT treatment was conducted by pressurizing orange juice and nitrogen at moderately high pressures (P?=?25 or 50 MPa) in a tubular continuous reactor. Abrupt decompression was achieved by a relief valve at the end of the tubular system. As compared to freshly squeezed juice, PCT treatment slightly reduced levels of carotenoids, vitamin C and hesperidin by 19, 5, and 14 %, respectively. Peroxidase was completely inactivated, whereas residual pectin methylesterase activities amounted to 26–27 %. Simultaneously, total aerobic plate counts were substantially reduced by at least 3.4 log10 cfu/mL. The mean volume-weighed particle diameter d 43 was drastically reduced from 652 μm in freshly squeezed juice to 6 and 31 μm at 25 and 50 MPa, respectively. Concomitantly, CIE-L*a*b* color values indicated a brighter and more intense yellow color of PCT-treated juices. While cloud separation in freshly squeezed juice was completed within 3 days, cloud stability in PCT-treated juices was retained for 5 days. 相似文献
11.
F.J. García-Alonso M.J. Periago M.L. Vidal-Guevara E. Cantos G. Ros R Ferreres P. Abellán 《Journal of food science》2003,68(4):1525-1530
A 1‐y storage trial was designed involving different temperatures (8, 21, and 30 °C) to assess the antioxidant properties of a dessert formulated with concentrated juices of grape, blackberry, blackcurrant, raspberry, and cherry. The total antioxidant activity (TAA) of the dessert was measured as the scavenging capacity of the 2,2′‐azino‐di‐[3‐ethylbenzothiazoline‐6‐sulphonate] radical cation (ABTS) and as its iron‐reducing ability (FRAP). Color was spectrophotometrically measured, and vitamin C and phenolics were analyzed by HPLC. The color parameters and the concentrations of different antioxidant compounds were affected by storage conditions, especially in samples stored at 30 °C, although the TAA remained practically invariable during storage. 相似文献
12.
Lucía Ortiz Eva Dorta M. Gloria Lobo L. Antonio González-Mendoza Carlos Díaz Mónica González 《Food and Bioprocess Technology》2017,10(10):1883-1891
Banana peel extract (BPE) was added to freshly squeezed orange juices (FSJ) and orange juices from concentrate (JFC), in order to evaluate if it stabilises their antioxidant activity, sensory attributes and physicochemical characteristics after heat treatment and during refrigerated storage. Mild pasteurisation increased shelf life in refrigeration for both types of orange juice, although JFC was more stable than FSJ. Antioxidant activity, determined as ABTS?+ scavenging capacity, tends to decrease with refrigeration time. However, when BPE was added, pasteurised juices tend to have greater capacity to scavenge ABTS?+ over time. No relevant effects were observed on the capacity to inhibit lipid peroxidation. Panellists found it extremely difficult to detect differences between juices with BPE and conventional ones. Moreover, panellists found the juices with BPE were more acceptable than conventional ones, although some modifications became more evident over time. The sensory quality of the JFC remained more stable during storage than that of FSJ. Juice colour changed slightly after heat treatment, but these changes tended to disappear over time. Adding BPE increased the total soluble solid content in all FSJ and in unpasteurised JFC. Adding BPE or pasteurising did not produce significant changes in pH in either type of juice. An increase of pH and acidity was detected in all the FSJ (except in acidity of juices without BPE) with time of refrigeration. 相似文献
13.
Commercial quality, major bioactive compound content and antioxidant capacity of 12 cultivars of loquat (Eriobotrya japonica Lindl.) fruits 总被引:1,自引:0,他引:1
BACKGROUND: Modern consumers are increasingly interested in their personal health and expect the food they purchase to be tasty and attractive while being safe and healthful. The aim of this study was to determine the commercial quality, characterise the antioxidant capacity and quantify the major bioactive compounds of 12 cultivars of loquat fruits in order to establish a database for utilising these germplasm resources. RESULTS: Of the 12 cultivars, ‘Guanyu’ produced the biggest fruits, while ‘Tianzhong’ and ‘Bingtangzhong’ had the highest soluble solids content but the lowest titratable acidity. ‘Taipinghong’ was reddest in colour. Sucrose, fructose, glucose and sorbitol were the major sugars in loquat fruits, with the highest total sugar content being observed in ‘Bingtangzhong’ and ‘Tianzhong’. Phenolics and flavonoids were the main bioactive compounds and were abundant in ‘Tianzhong’ and ‘Zhaozhong’. ‘Taipinghong’ had the highest total carotenoid content, while ‘Qingzhong’ had the highest vitamin C content. ‘Tianzhong’, ‘Bingtangzhong’ and ‘Ninghaibai’ showed higher antioxidant activity than the other cultivars, as measured by assays of 1,1‐diphenyl‐2‐picrylhydrazyl (DPPH) and 2,2‐azino‐bis(3‐ethylbenzthiozoline‐6‐sulfonic acid) (ABTS) scavenging and ferric‐reducing/antioxidant power (FRAP). CONCLUSION: Commercial fruit quality, major bioactive compound content and antioxidant capacity varied greatly among the 12 cultivars. ‘Bingtangzhong’ and ‘Tianzhong’ were the highest‐ranking cultivars based on their good commercial quality and high nutritional value. The loquat fruits with higher total phenolic and flavonoid contents also had clearly higher antioxidant capacities. Copyright © 2011 Society of Chemical Industry 相似文献
14.
The influence of natural sweetener (Stevia rebaudiana Bertoni) on bioactive compounds content in chokeberry juice
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Jana Šic Žlabur Nadica Dobričević Ante Galić Stjepan Pliestić Sandra Voća 《Journal of Food Processing and Preservation》2018,42(1)
The aim was to determine the differences in nutritional quality between chokeberry juices sweetened with sucrose and green stevia powder. The quality of chokeberry juices during refrigerated storage was studied. Chokeberry juices with added green stevia powder had the higher content of analyzed bioactive compounds in comparison with juice samples sweetened with sucrose; vitamin C content increased up to two times, total phenol content up to 6% and antioxidant capacity for 3%. The content of studied bioactive compounds and antioxidant capacity during storage in period of 30 and 60 days was significantly reduced with the exception of steviol glycosides which content was not significantly reduced during the storage period.
Practical applications
Chokeberry juice is a popular, widespread product of chokeberry fruit characteristic for the dark intense red color, slightly unpleasant, bitter taste and extremely rich bioactive compounds content. Because of high nutritional quality, chokeberry juice is often consumed but with the biggest barrier of characteristic astringent taste which can be diminished by addition of sweetener. Producers often combine a low‐cost sweeteners like sucrose which shows numerous negative effects on human health. A good alternative to the sucrose and artificial sweeteners are natural sweeteners extracted from the plant material like steviol glycosides. Except sweetness, stevia products like green powder shows beneficial effect on the bioactive compounds content in the juices sweetened with it. Juices sweetened with stevia shows increased content of bioactive compounds, so such product may represent quality product from category of functional food. 相似文献15.
Yang X Kang SM Jeon BT Kim YD Ha JH Kim YT Jeon YJ 《Journal of the science of food and agriculture》2011,91(10):1925-1927
BACKGROUND: Large amounts of citrus by‐products are released from juice‐processing plants every year. Most bioactive compounds are found in the peel and inner white pulp. Flavonoids are a widely distributed group of bioactive compounds. The methanolic extract of citrus peel powder has been shown to possess strong antioxidant activity. Therefore the aim of this study was to isolate the major antioxidant flavonoid compound from Citrus unshiu (satsuma) peel as citrus by‐product and evaluate its antioxidant activity. RESULTS: The major flavonoid isolated from C. unshiu peel was identified as quercetagetin. The structure of the compound was determined by tandem mass spectrometry and ultraviolet spectroscopy. Its antioxidant activity was assessed by assays of 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) radical, hydroxyl radical and intracellular reactive oxygen species (ROS) scavenging and DNA damage inhibition. Quercetagetin showed strong DPPH radical‐scavenging activity (IC507.89 µmol L?1) but much lower hydroxyl radical‐scavenging activity (IC50203.82 µmol L?1). Furthermore, it significantly reduced ROS in Vero cells and showed a strong protective effect against hydrogen peroxide‐induced DNA damage. CONCLUSION: The results of this study suggest that quercetagetin could be used in the functional food, cosmetic and pharmaceutical industries. Copyright © 2011 Society of Chemical Industry 相似文献
16.
为了探讨MeJA处理对枇杷果实抗氧化能力的影响,研究了10μmol/L MeJA处理的"大红袍"枇杷果实在1℃贮藏过程中维生素C、总酚、总黄酮、总类胡萝卜素含量及抗氧化活性的变化。结果表明,枇杷果实在贮藏过程中维生素C和总黄酮含量下降,而总酚和总类胡萝卜素含量呈先上升后下降的趋势。10μmol/L MeJA处理可显著抑制果实中维生素C和总黄酮含量的下降,促进贮藏前期总酚和总类胡萝卜素含量的上升。在1℃贮藏过程中,枇杷果实DPPH和超氧阴离子自由基清除能力随着贮藏时间的延长呈先上升后下降趋势,并且抗氧化活性的变化与总酚和总类胡萝卜素含量的变化呈显著正相关,而与维生素C和总黄酮含量的变化相关性较低。这表明MeJA是通过影响枇杷果实中酚类和类胡萝卜素物质的代谢来维持枇杷果实采后较高的抗氧化能力和营养价值。 相似文献
17.
Min-Ju Kim Jung-Guy Jun Shin-Young Park Mi-Joo Choi Eunju Park Jung-In Kim Myo-Jeong Kim 《Food science and biotechnology》2017,26(4):861-869
The purpose of this study was to evaluate and compare the antioxidant activities, and their contents, in grape juices prepared by various household juicers, and grape flesh (GF). The grape juices were prepared using a low-speed masticating (LSM) juicer, a high-speed centrifugal (HSC) juicer, and a blender (BLD). The total polyphenol, total flavonoid, total monomeric anthocyanin, and vitamin C contents were highest in the LSM grape juice, and decreased in the order: LSM > BLD > HSC > GF. The antioxidant activities such as DPPH radical scavenging activity, and SOD-like activity were significantly higher in the LSM juice than in other juices and grape flesh. The antioxidant activities and the quality of grape juices were significantly affected by the household juicing method used, and an LSM juicer is strongly recommended for making healthy grape juice, rich in antioxidants. 相似文献
18.
Karina Cardoso Tramonte João Gustavo Provesi Iolanda Moreira Dutra Albuquerque E Silva Aureanna Nairne Negrão Murakami Marcelo Maraschin Renata Dias De Mello Castanho Amboni Edna Regina Amante 《International Journal of Food Science & Technology》2011,46(9):1871-1877
The heart of palm is a food extracted from several species of palm trees. Only 10–20% of the raw material is transformed into canned hearts of palm, therefore this agro‐industry generates a large quantity of solid residue. The aim of this work was to extract and characterise a juice produced from this solid residue. This extract is compared with the traditional fruit juices (orange and pineapple juices), obtaining higher contents of minerals, such as magnesium (22.80 mg/100 g) and potassium (276.90 mg/100 g), phenolic compounds (gallic, 3,4‐dihydroxybenzoic, chlorogenic, syringic and caffeic acids) and high free radical scavenging capacity (expressed as 2,2‐diphenyl‐1‐picrylhydrazyl), which suggest high antioxidant activity. Additionally, a new soft drink was formulated using this king palm juice as its main ingredient. The soft drink samples formulated with this juice had high sensory acceptability and high intention of consumption, which suggests an important and low‐cost application for this industrial residue. 相似文献
19.
Frozen orange juice concentrate (63.8° Brix) was reconstituted with water to single strength juice and supplemented with a commercial citrus pectinesterase (PE) to give an activity of 1.5 PE units/mL juice. Reconstituted juice and freshly squeezed single strength orange juice were treated with a cation exchange resin. Resin treatment decreased the pH of the juice from 3.75 to 2.0 and completely inactivated PE. PE was also inactivated following acidification of the juice to pH 2.0 with concentrated hydrochloric acid. Very little cloud loss occurred in refrigerated (4°C) juice at pH 2.0 for approximately 12 wk; however, a loss (> 95%) of ascorbic acid resulted. Only microorganisms died-off rapidly (> 99.9%) in juices adjusted to pH 2.0 using ion exchange resin, but not in juices lowered to pH 2.0 with HCl. 相似文献
20.
Inactivation of Salmonella Typhimurium in orange juice containing antimicrobial agents by pulsed electric field 总被引:2,自引:0,他引:2
Combinations of different hurdles, including moderately high temperatures (<60 degrees C), antimicrobial compounds, and pulsed electric field (PEF) treatment, to reduce Salmonella in pasteurized and freshly squeezed orange juices (with and without pulp) were explored. Populations of Salmonella Typhimurium were found to decrease with an increase in pulse number and treatment temperature. At a field strength of 90 kV/cm, a pulse number of 20, and a temperature of 45 degrees C, PEF treatment did not have a notable effect on cell viability or injury. At and above 46 degrees C, however, cell death and injury were greatly increased. Salmonella numbers were reduced by 5.9 log cycles in freshly squeezed orange juice (without pulp) treated at 90 kV/cm, 50 pulses, and 55 degrees C. When PEF treatment was carried out in the presence of nisin (100 U/ml of orange juice), lysozyme (2,400 U/ml), or a mixture of nisin (27.5 U/ml) and lysozyme (690 U/ml), cell viability loss was increased by an additional 0.04 to 2.75 log cycles. The combination of nisin and lysozyme had a more pronounced bactericidal effect than did either nisin or lysozyme alone. An additional Salmonella count reduction of at least 1.37 log cycles was achieved when the two antimicrobial agents were used in combination. No significant difference (P > 0.05) in cell death was attained by lowering the pH value; only cell injury increased. Inactivation by PEF was significantly more extensive (P < 0.05) in pasteurized orange juice than in freshly squeezed orange juice under the same treatment conditions. This increase might be due to the effect of the chemical composition of the juices. 相似文献