The effects of processing technology on the patulin content of juice during commercial apple juice concentrate production

 The effects of different treatments on the patulin content of apple juice during the production of industrial apple juice concentrate were investigated. Conventional clarification using a rotary vacuum precoat filter was found to be more effective than using ultrafiltration for the removal of patulin from apple juice. The average losses of patulin were 39% and 25% for conventional clarification and filtration, and ultrafiltration, respectively. Washing and handling appeared to be the most critical steps in removing patulin from apples since up to 54% could be removed using high-pressure water spraying. Received: 22 January 1998 / Revised version: 21 April 1998     

Effect of thiamine hydrochloride,pyridoxine hydrochloride and calcium‐d‐pantothenate on the patulin content of apple juice concentrate

Thiamine hydrochloride, pyridoxine hydrochloride and calcium‐d‐pantothenate were applied apple juice concentrates (AJC) at various doses in order to reduce the patulin content. AJC samples containing high levels of patulin were stored at 22 ± 2°C and 4°C for 6 months after vitamins were added. Patulin was fully degraded at the end of a 6‐month period in samples stored at 22 ± 2°C, on the other hand, other quality parameters diminished significantly. Without any considerable reduction on other quality parameters, applications of 1000 and 2500 mg/kg calcium‐d‐pantothenate resulted in reduction of patulin of 73.6 and 94.3%, respectively, however, 42.1% of patulin reduction was observed in the control sample of AJC stored for 1 month at 22 ± 2°C. Addition of thiamine hydrochloride (1000 mg/kg( pyrodoxine hydrochloride (625 or 875 mg/kg) and calcium‐d‐pantothenate (1000 or 2500 mg/kg) into the samples and storage at 4°C for 6 months yielded 55.5 to 67.7% of patulin reduction which was only 35.8% for the control, while the other quality parameters were protected adequately.     

Free and bound patulin in cloudy apple juice

During validation of an HPLC-UV method for patulin analysis, a time and concentration dependent recovery of patulin was observed. Spiked cloudy apple juice was analysed on successive days, which resulted in recoveries on day 3 which were up to 20% lower than on day 1. This reduction was caused by an interaction between patulin and the solid parts of cloudy apple juice. Since these solid parts are richer in proteins compared to the liquid phase of cloudy apple juice, and the binding of patulin to proteins has been described in the literature, patulin will most probably interact with the proteins in the solid parts. As a consequence, up to 20% of the present patulin is bound and not detected during HPLC-UV analysis, which can lead to an underestimation on toxicological level.     

浓缩苹果汁加工链中棒曲霉素的动态分析研究

研究了浓缩苹果汁加工过程中各工序对棒曲霉素含量的影响。结果表明,喷淋、拣选、清洗是去除棒曲霉素的关键步骤,去除率为60.18％;吸附树脂对棒曲霉素去除效果显著。此外,研究了加工季节中棒曲霉素的变化规律,为果汁加工厂家建立科学完善的HACCP管理体系提供了理论依据。     

The effects of different technologies on<Emphasis Type="Italic"> Alicyclobacillus acidoterrestris</Emphasis> during apple juice production

In this study, the effects of various processing steps applied during apple juice processing on Alicyclobacillus acidoterrestris were investigated. Raw apple juice was inoculated with A. acidoterrestris spores at two inoculum levels of 1×10³ cfu/ml and 1×10⁶ cfu/ml. Following enzymatic treatment, the raw juice was processed into clear juice using either conventional clarification or ultrafiltration. The number of A. acidoterrestris spores in the final product was determined to be dependent on both initial contamination level and processing conditions. Increasing temperature to 50 °C during depectinization resulted in a higher spore counts at both inoculum levels. Even if the ultrafiltration process was found to be much more convenient for the retention of A. acidoterrestris when compared to conventional clarification, the spores could penetrate the ultrafiltration membranes having both 20 and 50 kDa. Increasing membrane pore size and initial spore counts in the feed solution also increased the number of spores penetrating the membrane during ultrafiltration.     

Effect of apple cultivar and enzyme treatment on phenolic compounds content during clear apple juice production

The aim of the investigation was evaluation of phenolic compounds content, measured by HPLC method at selected stages of clear apple juice production with pectolytic mash enzymation from ‘Shampion’ and ‘Idared’ apples. Sum of phenolic compounds in ‘Shampion’ mash was significantly higher than in ‘Idared’ mash, 520 and 352 mg kg^?1, respectively. Enzymation of ‘Idared’ mash resulted in a higher phenolic compounds decrease compared to ‘Shampion’, 23% and 14% respectively. Sum of phenolics in juices from ‘Shampion’ for Panzym at 50 °C (366 mg kg^?1) was significantly higher than in juices from ‘Shampion’ for Rohapect at 20 °C and ‘Idared’ for Panzym at 50 °C (256 and 234 mg kg^?1, respectively). The lowest phenolics (95 mg kg^?1) was in juices from ‘Idared’ for Rohapect at 20 °C. There was a positive correlation (R² = 0.933) between phenolics content and antioxidant activity of juices (ABTS^?+). In general, enzymation at 50 °C with Panzym lead to a higher content of the phenolic compounds in juices compared to Rohapect at 20 °C.     

Analysis of the fouling mechanisms during cross-flow ultrafiltration of apple juice

The purpose of this work was to study the fouling mechanisms of a Carbosep^® M8 membrane during the cross-flow ultrafiltration of apple juice. A new fouling model has been developed that simultaneously considers membrane blocking within the pores, at the pore mouths and by cake formation at the membrane surface. Membrane fouling by apple juice was due to internal pore blocking as well as cake formation. When operating ultrafiltration at a transmembrane pressure of 150 kPa and a cross-flow velocity of 7 m/s, fouling was minimal with a gradual decrease of the relative contribution of cake formation; however, transmembrane pressure still exceeds critical pressure. The fouling model predicts no cake formation at a cross-flow velocity of 7.4 m/s and a transmembrane pressure of 150 kPa or at a cross-flow velocity of 7.0 m/s and a transmembrane pressure of 120 kPa. Under these conditions, internal membrane blocking would be the only mechanism responsible for the decrease of permeate flux.     

The reduction of patulin in apple juice by three different types of activated carbon

Three types of activated carbon (NORIT SA 4, NORIT SX 4 and NORIT CA 1) were investigated for their ability to reduce patulin levels in apple juice at various Brix levels and temperatures. The steamactivated carbons (NORIT SA 4 and NORIT SX 4) exhibited similar adsorption isotherms at a dosage level of 1g/l. They achieved patulin reductions of 80% and 70% respectively in 12° Brix juice at 55°C. The similarity in performance between the steam-activated carbons implies that the purity and the surface acidity does not influence the adsorption of patulin. Chemically-activated carbon (NORIT CA 1) was less effective in removing patulin and achieved only a 45% reduction at a dose of 1g/l. Patulin removal was influenced by juice Brix in that higher carbon doses were required at higher Brix levels for equivalent removal efficiency. At a dose of 1g/l, NORIT SA 4 removed only 45% patulin from a 20° Brix juice. The removal of patulin from either 12 or 20° Brix juice by NORIT SA 4 at 1g/l was not influenced by temperature changes in the range 30 to 65°C.     

Effect of ultrafiltration on concentrated apple juice colour and turbidity

Colour and turbidity of conventional bentonite-gelatin clarified apple juice was compared with 30,000–50,000 and 100,000DA hollow fibre ultrafiltered apple juice, with and without pectinolytic enzyme treatment. Results indicated that objective quality of ultrafiltered apple juice compared favourably with conventionally clarified apple juice over 30 weeks of storage at 37.5°C. However, treatment with pectinolytic enzymes before ultrafiltration increased both the initial colour and the browning rate. No significant differences were found in the values of the transmission haze after storage.     

复合酶在苹果汁加工中的应用研究

将纤维素酶与α-淀粉酶结合果胶酶用于苹果汁加工过程中的液化与澄清,弥补现行果胶酶在酶系上的不足。通过正交实验获得了液化与澄清工艺的最佳组合参数,对于苹果汁的加工生产具有实际指导意义。     

清洁生产在浓缩苹果汁加工厂节水减污中的应用

通过对浓缩苹果汁加工厂用水量及排水水质的监测,确定重点节水减污单元。在清洁生产思想的指导下改进重点节水减污单元生产工艺并加强管理,达到了节水减污的目的。     

清洁生产在浓缩苹果汁加工厂节水减污中的应用

通过对浓缩苹果汁加工厂用水量及排水水质的监测，确定重点节水减污单元。在清洁生产思想的指导下改进重点节水减污单元生产工艺并加强管理，达到了节水减污的目的。     

雪梨汁护色、澄清技术研究

本实验以雪梨为原料,研究了维生素C、亚硫酸氢钠和柠檬酸等不同护色剂对梨汁色泽的影响,及果胶酶、PVPP(聚乙烯聚吡咯烷酮)和壳聚糖等澄清剂对梨汁澄清效果的影响,并采用正交实验的方法,确定了果汁复合护色与澄清的适宜组合。结果表明:雪梨破碎后经浓度为0.8g/L的维生素C、5g/L的柠檬酸和0.2g/L的亚硫酸氢钠复合液浸泡对梨汁护色效果较好;采用0.2mL/L果胶酶、0.3g/LPVPP、0.4g/L壳聚糖澄清梨汁效果较好。     

Effect of ozone processing on the colour,rheological properties and phenolic content of apple juice

Apple juice samples were ozonated with processing variables of ozone concentration (1–4.8% w/w) and processing time (0–10 min). Effects of processing variables on colour values (L, a and b), rheological properties and phenolic content were studied. Significant reductions in these parameters were observed during ozonation. Second order polynomial regression modelling was used to investigate the main effects of ozone concentration and processing time on the changes in the selected quality parameters of ozonated apple juice. Predicted models were found to be significant (p < 0.05) with low standard error and high coefficients of determination (R²).     

Determination of patulin in apple juice using magnetic solid-phase extraction coupled with high-performance liquid chromatography

ABSTRACT

An efficient magnetic sorbent consisting of benzofuran-2-carboxylic acid-loaded magnetic nanocomposite was successfully synthesised for pre-concentration of patulin from apple juice. The prepared magnetic nanocomposite was characterised by scanning electron microscopy, transmission electron microscopy and Fourier-transform infrared spectroscopy. Determination of enriched patulin was performed by high-performance liquid chromatography. The best adsorption conditions were 40 mg of sorbent, 50 ml of apple juice sample, pH 5, ambient temperature and 25 min; the elution conditions were 500 μl methanol, pH 5, ambient temperature, and 4 min. Under optimised conditions, pre-concentration factor was 100, linearity range was 1–400 μg l^–1 of patulin, limit of detection was 0.15 μg l^–1 and limit of quantification was 0.5 μg l^–1. When samples were determined 20 times, the recovery was 93.9–102.6% and the relative standard deviation was below 5.3%. In terms of proposed procedure, the developed method was successfully applied for patulin detection in apple juice samples.     

Standardisation of the detection of invert sugar addition to apple juice by capillary gas chromatography

 Capillary gas chromatography (CGC) can be used to check the authenticity of various fruit juices by analysing their oligosaccharide fingerprint profile. Thus, it enables the analyst to detect, for instance, the dilution of apple juice concentrates with cheaper sweeteners such as invert sugar syrup. In order to detect this, two marker peaks (IS1 and IS2) that are present in most invert sugar syrups are monitored in the CGC chromatogram of apple juice. In freshly pressed apple juice, these peaks are normally not found. As a result of apple juice processing and, in particular, the thermal treatment required to concentrate and pasteurise the juice, these peaks may however be present in authentic apple juice concentrate and juice made from it. It is nevertheless possible to distinguish between juice showing this "heat effect" and that to which invert sugar has been added since the IS2/IS1 peak ratio is very different in heated apple juice and in invert sugar syrups. Measuring this ratio and setting a maximum IS2/IS1 cut-off limit enables the analyst to assess whether the sample meets the set norms or has been adulterated. In the past, many laboratories experienced difficulties when comparing the results of this analysis and, in particular, IS2/IS1 peak ratios. We present evidence that this unsatisfactory situation is mainly due to the chromatographic behaviour of the IS1 peak. It appears indeed to be difficult to set up chromatographic conditions in all laboratories in order to produce reproducible results of the IS2/IS1 ratio. We have therefore examined the possibility of standardising results of this analysis and demonstrate that the comparison of any unknown apple juice sample with an external apple juice reference sample enables different laboratories to reach similar conclusions. The IS2/IS1 peak ratio in this reference sample was adjusted to the significant cut-off limit. The assessment (fail or pass) is thus based on a standardised IS2/IS1 ratio that is independent of several important analytical parameters which tend to strongly influence it. Received: 26 December 1997 / Revised version: 30 March 1998     

Standardisation of the detection of invert sugar addition to apple juice by capillary gas chromatography

 Capillary gas chromatography (CGC) can be used to check the authenticity of various fruit juices by analysing their oligosaccharide fingerprint profile. Thus, it enables the analyst to detect, for instance, the dilution of apple juice concentrates with cheaper sweeteners such as invert sugar syrup. In order to detect this, two marker peaks (IS1 and IS2) that are present in most invert sugar syrups are monitored in the CGC chromatogram of apple juice. In freshly pressed apple juice, these peaks are normally not found. As a result of apple juice processing and, in particular, the thermal treatment required to concentrate and pasteurise the juice, these peaks may however be present in authentic apple juice concentrate and juice made from it. It is nevertheless possible to distinguish between juice showing this "heat effect" and that to which invert sugar has been added since the IS2/IS1 peak ratio is very different in heated apple juice and in invert sugar syrups. Measuring this ratio and setting a maximum IS2/IS1 cut-off limit enables the analyst to assess whether the sample meets the set norms or has been adulterated. In the past, many laboratories experienced difficulties when comparing the results of this analysis and, in particular, IS2/IS1 peak ratios. We present evidence that this unsatisfactory situation is mainly due to the chromatographic behaviour of the IS1 peak. It appears indeed to be difficult to set up chromatographic conditions in all laboratories in order to produce reproducible results of the IS2/IS1 ratio. We have therefore examined the possibility of standardising results of this analysis and demonstrate that the comparison of any unknown apple juice sample with an external apple juice reference sample enables different laboratories to reach similar conclusions. The IS2/IS1 peak ratio in this reference sample was adjusted to the significant cut-off limit. The assessment (fail or pass) is thus based on a standardised IS2/IS1 ratio that is independent of several important analytical parameters which tend to strongly influence it. Received: 26 December 1997 / Revised version: 30 March 1998     

刺葡萄汁饮料生产工艺研究

研究用湖南产刺葡萄试制饮料的最佳护色和澄清工艺.结果表明:刺葡萄饮料的最佳护色工艺为70℃保温5 min.最佳澄清工艺为6000r/min离心10 min.     

苹果浓缩汁生产工艺对酚类物质影响的研究

为了提高苹果浓缩汁的色值指标,采用HPLC法,对苹果浓缩汁生产单元操作中酚类物质的含量进行检测。实验结果表明:杀菌、酶解、吸附这三步操作同时影响果汁中的酚类物质含量。选择性地去除有颜色的多酚氧化产物,是理想的苹果浓缩汁加工工艺。     

Effect of previous enzymatic recirculation treatment through a tubular ceramic membrane on ultrafiltration of model solution and apple juice

The process of ultrafiltration of a model solution and 12% soluble solids apple juice containing pectins through tubular membranes of 100 and 300 kDa (1 and 3 channels) was studied. Furthermore, in order to obtain a higher permeate flow, the fluids were previously treated with pectinolytic enzymes recirculating through a tubular membrane at different concentrations and treatment times. The permeate flow was analyzed with respect to time and the influence of enzymatic treatment on different parameters: viscosity, density, absorbance at 420 nm, reducing sugars, °Brix, color and pH. Depectinization increased the permeate flow for the model solution and apple juice with 67.52% and 53.11% when the pectinolytic enzyme preparation re-circulated across the tubular membrane. Using the lowest concentration of enzyme treatment and the longest recirculation treatment, an increase in permeate flow was obtained leading to a more favourable clarification process and economic benefits.