Industry-scale microfluidizer system produced whole mango juice: Effect on the physical properties,microstructure and pectin properties

Whole mango juice (WMJ) was prepared by the innovatively designed industry-scale microfluidizer system (ISMS). The effects of processing pressure (0–120 MPa) on physical properties, microstructure and pectin properties of WMJ were investigated. Results showed that ISMS effectively improved the physical stability of WMJ. The instability index reduced from 0.694 to 0.335, and the precipitate weight ratio increased from 22.04% to 30.08%, as the pressure increased from 0 to 120 MPa. Meanwhile, the particle size of WMJ gradually decreased, the cell wall structure was destroyed, the water-soluble pectin (WSP) contents increased, and accompanied with the narrowed distribution and decreases in the molecular weight of WSP. Atomic force microscopy imaging showed that the WSP polymers depolymerization occurred during ISMS processing. The particle size reduction, cell wall destruction, and WSP degradation contributed to the improved physical stability of WMJ. Therefore, ISMS can successfully produce WMJ with good physical stability at an industrial level.Industrial relevance: The production of whole juices without filtration has become a trend due to the retention of nutrients and environmental friendliness. However, the stratification and sedimentation hinder the development of whole juices. The findings in this study reveal that ISMS can be applied to produce whole mango juices due to its good pulverizing effect on the large-size cell walls. This study also gives important indications that ISMS may be used for processing industrial whole mango juices with good physical stability to obtain nutritional products.     

Impact of Thermal and Pressure-Based Technologies on Carotenoid Retention and Quality Attributes in Tomato Juice

The aim of this study was to investigate the impact of thermal processing (TP) (90 °C, 90 s), high-pressure processing (HPP) (600 MPa, 46 °C, 5 min), and high-pressure homogenization (HPH) (246 MPa, 99 °C, <1 s) on product quality parameters, specifically carotenoid content, and physicochemical attributes of particle size, color, viscosity, total soluble solids, and pH in tomato juice. Unprocessed tomato juice was used as control. The four major species of carotenoids (lycopene, β-carotene, phytoene, and phytofluene) in tomato juice were analyzed by HPLC. The content of total lycopene, all-trans-lycopene, cis-lycopene isomers,  phytoene, and phytofluene, in TP-, HPP-, and HPH-treated tomato juice did not significantly differ from that in unprocessed (control) juice. Significant reduction in β-carotene content was observed after TP treatment but not after HPP and HPH treatments. HPH significantly reduced tomato juice particle volume mean diameter from ～330 μm in control, HPP-, and TP-treated tomato juices to ～17 μm. A concomitant increase in apparent viscosity was observed in HPH-treated juice versus control. HPH-treated juice had increased redness (a*) and yellowness (b*) than that in control and HPP-treated tomato juices. These results indicate that high-pressure-based technologies (HPP and HPH) can preserve carotenoids as well as improve physicochemical properties.     

Effect of high pressure homogenization (HPH) on the rheological properties of tomato juice: Time-dependent and steady-state shear

High pressure homogenization (HPH) is a non-thermal technology that has been widely studied as a partial or total substitute for the thermal processing of food. Although microbial inactivation has been widely studied, there are only a few works in the literature reporting the physicochemical changes caused in fruit products due to HPH, especially those regarding the rheological properties. The present work evaluated the effect of HPH (up to 150 MPa) on the time-dependent and steady-state shear rheological properties of tomato juice. HPH reduced the mean particle diameter and particle size distribution (PSD), and increased its consistency and thixotropy. The rheological results were in accordance with the PSD observed. The rheological properties of the juice were evaluated by the Herschel–Bulkley and Falguera–Ibarz models (steady-state shear) and Figoni–Shoemaker and Weltman models (time-dependent). The parameters of these equations were modelled as a function of the homogenization pressure. The models obtained described the experimental values well, and contributed to future studies on product and process development.     

The effect of exogenous enzymes and mechanical treatment on mango purée: Microscopic,mesoscopic, and macroscopic evaluation

This paper addresses to what extent mango purée macroscopic properties (consistency) is related to its particle physical properties such as mesoscopic (particle size) and microscopic (morphology) properties. To manipulate mango purée particle sizes, high pressure homogenization (HPH) was used. Commercial fungal and bacterial (cell wall) polysaccharide degrading enzymes without/with HPH (different sequences) were used to understand the contribution of specific (cell wall) polysaccharides and the relevant parameters to consistency changes. The results reflect that, unlike endo-cellulase, pectin methylesterase (PME) together with endo-polygalacturonase (PG), and α-amylase significantly contributed to consistency decrease. HPH only, although largely changing the particle size, did not change the purée consistency, but the combination of HPH with an enzymatic treatment decreased it substantially. Enzymes, while having minimal effect on particle sizes, induced a type-dependent modification of particles’ morphology, showing the accessibility of particle polymers (in addition to the expected serum polymers) to enzymes.Industrial relevanceHigh consistency of mango purée that limits its processing is industrially decreased by dilution with water, requiring further flavor reconstitution and sugar addition. The consistency is believed to be related to pectin and starch. As physical and enzymatic pectin modifications are allowed by regulatory authorities, our study aimed at better understanding and controlling the flow properties of mango purée by both physical (high pressure homogenization) and enzymatic polysaccharides manipulations. Our findings highlight that in situ polysaccharide functionalization could be an industrially relevant alternative to commonly used additives in food systems for controlling the sensorial (i.e. taste and texture) properties.     

High-pressure homogenisation combined with blanching to turn lettuce waste into a physically stable juice

Lettuce waste was blanched, ground, pre-homogenised at 40 MPa and subjected to high pressure homogenisation (HPH) at 80 (1 pass) and 150 MPa (1, 10 passes) to obtain an ingredient intended for blended juice formulation. When lettuce was subjected to HPH without previous blanching, physically unstable juices were obtained. By contrast, the combination of HPH with a blanching pre-treatment allowed obtaining juices showing no physical separation and characterised by a bright green colour. This high stability was attributed to the modification of lettuce fibrous structure and to a 90% and 60% inactivation of polyphenoloxidase and pectin methylesterase, respectively. Juices presented a phenolic content of 3.5 ± 1.3 mg GAE/100 g and a microbial count at least 1 Log lower than that of corresponding not-blanched samples and below limits usually indicated for juice quality (4.7 Log CFU/g). During storage (4 °C), no phase separation was observed but microbial counts rapidly increased, suggesting the need for a further stabilization step.Industrial applicationSolid waste generated by fresh-cut processing of lettuce could be valorised by the application of blanching and HPH, leading to an innovative ingredient potentially exploitable in the formulation of healthy blended juices, smoothies and comminuted food. This effort is worth making considering that HPH is being increasingly introduced as processing operation in various industrial contexts, showing good feasibility and cost effectiveness, and could allow valorisation of different leaf discards.     

高压均质对NFC水蜜桃浊汁稳定性及品质的影响

本文采用高压均质技术,探究了均质压力（20~40 MPa）及次数（1~2次）对NFC水蜜桃浊汁的混浊度、离心沉淀率、粒径、Zeta电位等稳定性指标和pH、TSS、总酸、固酸比、还原糖、色泽、总酚、V_C等品质指标的影响。结果表明:高压均质（30~40 MPa/1、20~40 MPa/2）可有效提高NFC水蜜桃浊汁的稳定性,离心沉淀率较未处理组下降13.49%~24.22%,平均颗粒粒径由1853.67 nm降至501.10~665.27 nm,绝对Zeta电位值显著提高（P<0.05）。随着均质压力及次数的增加,浊汁中可溶性果胶含量上升,而残存果胶甲基酯酶活力逐渐降低。高压均质后,浊汁色泽显著改善,L*值升高,褐变指数BI值下降（P<0.05）;30 MPa/1下,品质保持最佳,总酚、V_C含量较未处理组显著提高（P<0.05）,而pH、TSS、总酸和固酸比无变化（P>0.05）;随着均质次数增加,pH、TSS、总酚和V_C含量显著降低（P<0.05）,品质下降。高压均质处理可有效提高NFC水蜜桃浊汁稳定性、抑制褐变,并提高总酚、V_C等营养物质含量。     

Effect of high pressure homogenization (HPH) on the rheological properties of tomato juice: Viscoelastic properties and the Cox–Merz rule

High pressure homogenization (HPH) is a non-thermal technology which has been widely studied as a partial or total substitute for the thermal processing of food. Although microbial inactivation has been widely studied, there are only a few papers in the literature reporting on physicochemical changes in fruit products due to HPH, especially regarding their rheological properties. The present work evaluated the effect of HPH (up to 150 MPa) on the viscoelastic properties of tomato juice. HPH increased the tomato juice storage (G′) and loss (G″) moduli. The parameters G′ and G″ were modelled as a power function of the oscillatory frequency (ω), and then evaluated as a function of homogenization pressure. It was observed that HPH processing improved tomato juice consistency more than it modified its nature/behaviour. The changes observed in the viscoelastic properties were attributed to disruption of the suspended particles during processing. Moreover, two modified Cox–Merz rules were used to correlate the products steady-state shear properties with viscoelasticity. The results obtained indicated that this process could be used to improve both product elastic and viscous behaviour, highlighting possible applications of the HPH process as a valuable tool to promote physical property changes in food products.     

Effect of high pressure processing on gastrointestinal fate of carotenoids in mango juice: Insights obtained from macroscopic to microscopic scales

High hydrostatic pressure (HHP) and high-pressure homogenization (HPH) were applied to mango juice to explore their effects on gastric retention rate (G-CRR), bioaccessibility (BAC) of total and individual carotenoids, and the corresponding mechanisms from macroscopic to microscopic scales. Compared to the control, both HHP and HPH at 50 MPa had no significant effect on BAC and G-CRR, whereas HPH at 100 MPa significantly increased BAC by 44.33% and G-CRR by 11.84%. Further HHP treatments (particularly at 400 MPa) on the 100 MPa-HPH-pretreated samples significantly increased BAC by 71.37% and G-CRR by 24.24%. Violaxanthins/esters were less stable than carotenes in the stomach, resulting in lower bioaccessibility of violaxanthins/esters. G-CRR and BAC were negatively correlated with the viscosity and particle size of juice, whereas they were positively correlated with the solubility/dispersibility of carotenoids. In addition, pectin-carotenoid interactions may also be an important factor affecting the digestive fate of carotenoids in juice.Industrial relevanceHigh pressure processing (High hydrostatic pressure, HHP, and high pressure homogenization, HPH) is a non-thermal technique and its effect on the bioaccessibility of carotenoids in fruits and vegetables have attracted attention from researchers. Our research found that HPH and HHP combined treatment could decrease the particle size of mango juice, and increase the viscosity and turbidity as well as the bioaccessibility of carotenoids therein. This technology can be used to preserve the physical stability of mango juice and improve the nutritional value.     

橙汁混浊稳定性的研究进展

橙子榨汁后,果肉颗粒、细胞壁碎片、橙油微滴、橙皮苷结晶、细胞色素及一些无定形物质不均匀的分散于水中,使橙汁呈现特殊的不透明或混浊状态,即\     

Simultaneous treatment of heat and high pressure homogenization of zein in ethanol–water solution: Physical,structural, thermal and morphological characteristics

The effects of high pressure homogenization (HPH) and/or heat treatment on the physical, structural, thermal and morphological characteristics of zein in ethanol–water solution were investigated. The results showed that HPH significantly reduced the size of zein nanoparticles. Both of HPH and heat treatment resulted in the increase of ultraviolet absorption and fluorescence intensity, as well as the enhanced thermal stability of zein. Compared with the individual HPH and thermal treatment, the coupled treatment of heat and HPH induced more obvious changes on the secondary structure of zein with the α-helix content increasing from 49.2% to 67.1%. The morphology of zein was greatly modified from sphericity to oval, dumbbell-like and random geometrical shape after HPH at 125 MPa. The synergistic effect was found between thermal treatment and HPH at 75 MPa, which resulted in size reduction of zein nanoparticles with the spherical shape and uniform distribution.Industrial relevanceThermal treatment has been extensively applied to modify the physiochemical properties of water soluble proteins like β-lactoglobulin, lactoferrin and livetins. However, the available reports on the heat-induced structural and physicochemical changes of alcohol-soluble proteins are limited.Nowadays, the new insight into protein modification is to apply physical treatments such as high pressure homogenization (HPH). HPH has been applied to modify the physiochemical, functional and structural properties of water soluble proteins, including faba bean protein, whey proteins, peanut proteins and soy protein isolate. However, little information is available about the effect of HPH treatment on structural modifications of alcohol-soluble proteins. Besides, according to the previous literatures, the combined treatment of thermal with HPH is commonly employed to improve the stability of dairy products. Nevertheless, to our best knowledge, there is no report about the coupled treatment of thermal and HPH on the modification of ethanol-soluble protein.Results from present work can be used to confirm the hypothesis that the simultaneous treatment of thermal and HPH would be an attractive modification method for zein with better thermal behaviors and structural properties to develop new food grade materials, which could be useful in the development of the potential delivery systems for bioactive compounds.     

Effects of pulsed electric field treatment of apple mash on juice yield and quality attributes of apple juices

The influence of apple mash treatment with pulsed electric fields (PEF) on yield and quality attributes of the resulting cloudy juices were investigated. Apple juice was produced at laboratory scale (400 g apples per lot) by mash treatment with pulsed electric fields at three different field intensities (1, 3, 5 kV/cm, n = 30 pulses) and manual pressing at room temperature. The juices were compared with untreated control juices of the same mash and with a juice after pectolytic mash treatment. Relative to the control samples, juice yield increased with increasing field intensities. The overall composition as described by pH, total soluble solids, total acidity, density, contents of sugar, malic acid and pectin, respectively, as well as the nutritive value with respect to polyphenol contents and antioxidant capacities (TEAC, FRAP, DPPH) of the PEF-treated apple juices did not significantly differ from the controls.Industrial relevanceThis paper addresses the composition of apple juice after mash treatment applying pulsed electric fields and maceration enzymes, respectively. Since substantial equivalence of products derived from novel technologies, such as PEF, relative to their conventionally produced counterparts is required according to European food law, this aspect is of great relevance, especially for commercialisation of fruit juices based on PEF technology. Furthermore, the nutritional value of juices produced at different pulsed electric field activities is of relevance for their marketing.     

Modification of dietary fibers from purple-fleshed potatoes (Heimeiren) with high hydrostatic pressure and high pressure homogenization processing: A comparative study

In this study, we evaluated the effects of high hydrostatic pressure (HHP) and high pressure homogenization (HPH) treatments on the physicochemical, functional, and structural properties of dietary fibers (DFs) obtained from purple-fleshed potatoes. DFs subjected to HHP and HPH exhibited increased content of soluble dietary fiber. HHP and HPH treatments did not improve water holding capacity, but increased oil holding and swelling capacities, and emulsion activity and stability. DFs treated with HPH showed the increased antioxidant activities (DPPH 0.89, ABTS 2.65, FRAP 3.39 mg Trolox/g DF), content of total phenol, and α-glucosidase inhibition (98.3%). HHP and HPH treatments changed monosaccharide compositions and structural characteristics of DFs. Therefore, DFs from purple-fleshed potatoes could be used as a fiber-rich ingredient in functional foods, and HPH was more useful in the modification of dietary fiber than HHP at the same treatment conditions.Industrial relevance: This article deals with the modification of dietary fibers from purple-fleshed potatoes (Heimeiren) with HHP and HPH treatments. Results suggest that HPH treated dietary fiber showed a higher ratio of soluble fraction, increased physicochemical and functional properties than HHP at 200 MPa. There outcomes could help the food industry identify the optimal high pressure processing type to improve physicochemical and functional properties of dietary fiber.     

植物多酚的生理活性、抑菌机理及其在食品保鲜中的应用研究进展

果胶和多酚共存于植物性食品体系中。除天然存在的果胶-多酚复合物外,在受到加热、高压、干燥等外力作用的食品加工过程中,两者会快速且自发地进行相互作用。果胶与多酚之间的相互作用会影响食品的理化性质和功能特性。本文总结了果胶与多酚相互作用的机制、内部和外部多重影响因素、主要的研究方法并结合 Langmuir和Freundlich常见的等温吸附模型对果胶与多酚之间的吸附行为进行描述和定量表征。此外还探讨了两者相互作用对食品加工特性及多酚生物可利用性的影响,分析了该领域的研究方向和发展趋势。

     

Changes in orange juice characteristics due to homogenization and centrifugation

Two common operations in citrus plants are homogenization and centrifugation. By homogenization, the size of suspended particles decreases and, therefore, cloudiness and color intensity increase. By centrifugation, the total pulp content is controlled. The objective of this paper is to quantify the effect of these operations (and of their combination) on color, cloudiness, suspended pulp, particle size of cloud components, and pectin methylesterase (PME) activity, either in the whole juice or in the two fractions obtained by centrifugation. Results showed that homogenization at 20 MPa give low-pulp well-colored orange juices, although additional treatments are necessary to reduce residual PME activity. Juices with similar physical characteristics were obtained either when the whole juice was homogenized, or when homogenization was applied only to the pulpy fraction obtained by centrifugation and then blending this fraction back with the low pulp fraction.     

均质压力和稳定剂对复合果蔬汁体态稳定性研究

以番茄、草莓、胡萝卜和葡萄原汁制成的混浊型复合果蔬汁为试材,进行不同均质压力、稳定剂组合试验,考察复合果蔬汁的体态稳定性。结果表明:均质压力为30MPa时,复合果蔬汁的浊度和不稳定性悬浮物最小;复合稳定剂组合为黄原胶0.15%+CMC0.05%+果胶0.05%时其稳定效果最好。     

Grape juice obtained using steam extraction and other small‐scale extraction methods: phenolic content,antioxidant capacity and stability during storage

Grape juices made using small‐scale production techniques are widely consumed. The extraction procedures employed to produce them, however, can affect bioactive compounds and antioxidant activity in the final product. In this study, juices prepared using four extraction methods (steam, extractor, juicer and blender) were evaluated for soluble and hydrolysable polyphenol content, total anthocyanin content, antioxidant capacity, physicochemical characteristics and colour. Acceptance of steam‐extracted juices and their stability during storage were also evaluated. Steam extraction resulted in a higher soluble phenolic (1073 ± 58 mg gallic acid L^?1) and anthocyanin content (138 ± 22 mg cyanidin L^?1), as well as a higher antioxidant capacity when compared to juices prepared using other methods. Although steam‐extracted juice remained microbiologically stable during 24 months of storage, changes in phytochemical compounds and antioxidant capacity did occur. Our results indicate that steam‐extracted grape juices have high commercial potential.     

Study on the applicability of high-pressure homogenization for the production of banana juices

The aim of this preliminary study was to evaluate the potential applicability of high-pressure homogenization (HPH) for the production of banana juices. To this purpose, a prototype equipment working up to 400 MPa and a lab-scale homogenizer working up to 150 MPa were used. Temperature, microbial load, pectate lyase activity, colour and viscosity of the samples homogenized at increasing pressure were evaluated. Pressures higher than 200 MPa were needed to obtain 4 log unit reduction of total mesophilic bacteria and pectate lyase inactivation. Following HPH, banana juice resulted brighter and less viscous than the untreated one. Data suggest that HPH treatments could be a reliable technological alternative to conventional heat treatments for the production of added-value fruit juices. However, the homogenization design could play a critical role in affecting the product quality attributes. In fact, homogenization performed at the same operative pressure by using different equipment leads to different effects on product quality.     

Change of microbial and quality attributes of mango juice treated by high pressure homogenization combined with moderate inlet temperatures during storage

The effects of high pressure homogenization (HPH) on microbial inactivation and quality attributes (physio-chemical properties, bioactive components and antioxidant capacity) of mango juice, as well as their changes during storage at 4 °C and room temperature were investigated. Pressure levels ranged from 40 to 190 MPa, the inlet temperature from 20 °C to 60 °C and the number of passes from 1 to 5. Complete inactivation of molds and yeasts was achieved by 1 and 3 passes at 190 MPa and 60 °C, while total plate count was below 2.0 log₁₀ CFU/mL. No multiplication of microorganisms was observed in mango juice over 60 days of storage at 4 °C. HPH treatment could retain or even increase the carotenoids and total phenols by 11.8% and 21.4%, respectively, while significant reductions were found for heat treatment (HT) samples. During the storage of 60 days, HPH treatment also provided better preservation of color, bioactive components and antioxidant capacity of mango juice than HT.Industrial relevanceHigh pressure homogenization (HPH) is a novel non-thermal technique, particularly suitable for continuous production of liquid foods limiting thermal damage and promoting “freshness”. Results showed that high pressure homogenization had the advantage of notably reducing the microbial load to levels equivalent to thermal pasteurization. Moreover, HPH treatment was superior to heat treatment with regard to post-treatment levels of bioactive.     

Effects of Ultraviolet Light and High‐Pressure Processing on Quality and Health‐Related Constituents of Fresh Juice Products

Fresh juices are highly popular beverages in the global food market. They are perceived as wholesome, nutritious, all‐day beverages. For a fast growing category of premium juice products such as cold‐pressed juices, minimal‐processing nonthermal techniques such as ultraviolet (UV) light and high‐pressure processing (HPP) are expected to be used to extend shelf‐life while retaining physicochemical, nutritional, and sensory characteristics with reduced microbial loads. Also, UV light and HPP are approved by regulatory agencies and recognized as one of the simplest and very environmentally friendly ways to destroy pathogenic organisms. One of the limitations to their more extensive commercial application lies in the lack of comparative effects on nutritional and quality‐related compounds in juice products. This review provides a comparative analysis using 92 studies (UV light: 42, HPP: 50) mostly published between 2004 and 2015 to evaluate the effects of reported UV light and HPP processing conditions on the residual content or activity of bioactive compounds such as vitamins, polyphenols, antioxidants, and oxidative enzymes in 45 different fresh fruit and vegetable juices (low‐acid, acid, and high‐acid categories). Also, the effects of UV light and HPP on color and sensory characteristics of juices are summarized and discussed.