Phlorizin

Mitigation effects of phlorizin immersion on acrylamide formation in fried potato strips

Yali Yanga,b, Hailiang Shenc,d, Ting Liua,b, Yaoyao Wena,b, Furong Wanga,b, Yurong Guoa,b,*

Abstract

BACKGROUND: Several researches reported that natural polyphenols affected acrylamide formation of frying products. However, the effects of different variety of polyphenols on acrylamide formation were distinct. In this study, we isolated and purified phlorizin from apples and identified the influence of phlorizin immersion on acrylamide formation and sensory properties of fried potato strips with regarding to the immersion concentration, time and temperature.
RESULTS: The acrylamide formation of fried samples decreased as the phlorizin concentration increased from 0 to 0.3 g kg-1, and 0.14 g kg-1 could be selected as the suitable immersion concentration to dramatically inhibit acrylamide formation with considering the cost of industrial production. Additionally, the acrylamide formation significantly reduced from 8.71×10-3 to 2.13×10-3 g kg-1 lyophilized weight (LW) with immersion time from 0 to 120 min, and 60 min could be selected to significantly reduce acrylamide formation in consideration of efficiency of the large-scale industrial processing. However, the effect of phlorizin immersion temperature on acrylamide formation of fried samples was not significant. Compared to the fried samples without immersion, the phlorizin immersion improved the color properties and the changing of texture parameters was slight.
CONCLUSION: The fresh potato strips immersed in the phlorizin solution of 0.14 g kg-1 at 40 ℃ for 60 min before frying could significantly decrease acrylamide formation of fried samples and retain the majority of fresh sensorial properties. The significant correlations obtained between sensory properties and acrylamide content indicated the sensory properties could be used as the indicator of acrylamide levels during industrial processing.

Keywords: immersion concentration, immersion time, immersion temperature, acrylamide formation, texture, color, Pearson correlations

INTRODUCTION

The potato (Solanum tuberosum) is one of the world’s major agricultural crops.1 The frying potato products have been the very popular snacks 150 years ago, and are one-third of the total sales in the US market.2 According to the reports of acrylamide intake, the great dietary acrylamide exposure was the frying potato products,3 bakery products,4 coffee and breakfast cereals.5 Acrylamide is neurotoxic and genotoxic in humans6,7 and has been considered to be a probable human carcinogen,8,9 and mainly formed by the Maillard reaction of the asparagine and reducing sugars during heating.10,11 The FAO/WHO joint Expert Committee of Food Additives (JECFA)12 reported that the acrylamide average dietary exposure for general population worldwide was 1×10-3 g kg-1 bw day-1. Recently, lots of studies have been carried out to find solutions to mitigate the acrylamide formation during the heat-processing. Former strategies of reducing the acrylamide formation included modification of raw materials, optimization of processing methods and conditions,13,14 addition of exogenous additives,15,16 and etc. The plant polyphenols are safer and more acceptable by the consumers compared with the synthetic antioxidants of butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT).15 Some plant extracts containing a large amount of polyphenols17 which were classified into food additives in many countries, such as the apple and grape extract,18,19 were used to effectively reduce the acrylamide formation in the frying potato products.
The polyphenols of apple attracted considerable attention of the researchers, especially the phlorizin.20 The Phlorizin was dihydrochalcone compound and higher content of apple polyphenols. In apple trees, phlorizin is found primarily in the young shoots, roots, leaves and bark, while in the apple fruit, the most content of phlorizin is in the seeds, with middle content in the core and the skin, and the lowest content in the cortex.21 Gornas et al.22 studied the detailed composition of phenolic compounds in the different parts of apple fruit, and the phlorizin was the main identified phenolic compound (0.09-0.13 g kg-1 from the flesh part, 2.9019.60 g kg-1 from the seeds and 3.02-40.49 g kg-1 from the stems in the dry weight basis). Previously, phlorizin usually was considered as the anti-diabetic compound and a promising natural product for reducing the postprandial glycemia,23,24 due to inhibit the intestinal glucose uptake by the sodium D-glucose cotransporter 1.25
Some literature reported that the phenol compounds of apple fruit mitigated the acrylamide formation during heat-processing,11,19 but few researches determined the acrylamide inhibitory activity of phlorizin of fried potato products. Therefore, the objectives of this study are (1) to evaluate the mitigation effect of phlorizin on acrylamide formation, (2) to establish the optimum approach to ensure the lower content of acrylamide and retain the most of fresh-like properties in the fried potato strips.

MATERIALS AND METHODS

Chemicals

The canola oil was obtained from the local supermarket (Xi’an, China). Acetone and formic acid which were chromatographically pure and the phlorizin standard were purchased from Sigma (China).

Preparation of immersion solution and samples

Phlorizin immersion solution preparation

The phlorizin was isolated and purified as the previous paper of our laboratory.26 The phlorizin immersion solution (0.04 g kg-1, 0.08 g kg-1, 0.10 g kg-1, 0.14 g kg-1, 0.16 g kg-1, 0.18 g kg-1, 0.20 g kg-1 and 0.30 g kg1) was dissolved with the distilled water by a magnetic stirrer.

Fried potato strips preparation

Potato tubers (Solanum tuberosum) of Chungxi cultivar were commercialized in China and purchased from the local supermarket (Xi’an, Shaanxi, China). All potato samples had the same postharvest storage conditions and storied at 8 ± 1 ℃ and 95% relative humidity prior to use. In our experiment, the average weight of all potato samples was similar, about 250 ± 10 g. The samples were hand peeled and then cut into strips (0.8 × 0.8 × 6 cm) with a stainless steel strip cutting machine (Meizhikou household products Co., Ltd, Fujian, China). 200 g of potato strips were selected for the immersion process. The immersion conditions prior to frying were determined in the preliminary experiment (data not shown). The Phlorizin immersion conditions used during processing were:
a. Immersion concentration: 0 g kg-1 (water immersion), 0.04 g kg-1, 0.08 g kg-1, 0.10 g kg-1, 0.14 g kg-1, 0.16 g kg-1, 0.18 g kg-1, 0.20 g kg-1 and 0.30 g kg-1
b. Immersion time: 10, 20, 30, 60 and 120 min
c. Immersion temperature: 20 ℃, 30 ℃, 40 ℃ and 50 ℃
In order to access the effect of different phlorizin immersion concentrations on acrylamide formation of fried samples, the fresh potato strips were immersed at 40 ℃ for 60 min; to value the influence of different immersion time on acrylamide formation of fried samples, the fresh potato strips were immersed in the phlorizin solution of 0.14 g kg-1 at 40 ℃; to analyze the effect of different immersion temperature on acrylamide formation, the fresh potato strips were immersed in the phlorizin solution of 0.14 g kg-1 for 60 min. After immersion, the excess water on the potato strips was blotted out with the filter paper and the samples were fried in an electrical fryer (Youshang kitchen information technology Co., Ltd, Guangzhou, China) at 160 ℃ for 7 min. The weight ratio of fresh potato strips and canola oil was 1:5. The frying period was previously determined through the final color of fried potato strips. According to the color scale of the USDA standard for French fries, the final color of fried potato strips was fixed to standard 3.27 After frying, the samples were lyophilized with a LGJ-18C freeze-drying instrument (Beijing sihuan scientific instrument factory, Beijing, China), and then packed in the plastic bags at -20 ℃ for the further analysis.

Color measurement

The color parameter of potato strip samples was measured with a colorimeter (NS800, 3nh Inc., China) and the CIE L*, a* and b* color system. The L* (lightness), a*(greenness [-] to redness [+]), and b* (blueness [-] to yellowness [+]) were recorded and evaluated. The parameters of chroma (C*) and hue angle (H*) were calculated with a* and b* values.28,29 Nine replicates were taken for each experiment, and the results were expressed as the mean value ± standard deviation.

Texture profile analysis

The texture profile analysis (TPA) for hardness (N), cohesiveness (dimensionless), springiness (mm) and chewiness (N × mm) was measured with a texture analyzer (TAXT plus, Stable Microsystems, Surrey, UK). The length of potato strip was cut into 10.0 mm with a knife. The test conditions used for the TPA measurement were set to pre-test speed 0.83 mm s-1, test speed 0.83 mm s-1 and post-test speed 0.83 mm s1; a rest period of 5 s between the two cycles; and trigger force of 5 g. The maximum extent of the deformation was 10% of the original length.30 Nine replicates were taken for each experiment and the results were expressed as the mean value ± standard deviation.

Analysis of acrylamide

According to the gas chromatograph method (GC) described by Perkin Elmer,31 the determination of acrylamide was performed with a few modifications. The lyophilized power was weighted 1 g and combined with 10 mL 0.1 % formic acid solution on a wrist action shaker for 20 min, and then put the mixture in the refrigerator for 40 min to easily remove the top oil layer. A 3 mL of the supernatant (beneath the oil layer) was filtered through a 0.45 μm nylon syringe filter, removed and was stored for cleanup and analysis. The CarboPrepTM 200 solid-phase extraction (SPE) tube (6 mL, 500 mg) was preconditioned with 2 mL acetone and 2 mL 0.1% formic acid at the rate of one drop per second, and then discarded. 2 mL of the filtered extract solution was subjected to the SPE tube with only gravity flow. 0.5-1.0 mL water was used to wash the SPE tube and passed through the tube quickly. Then, use vacuum for 1 min to dry excess water from the SPE tube. 2 mL acetone was used to elute the SPE tube with gravity only, and the eluate solutions was collected for GC analysis.
The GC analysis of the extract samples was performed on the GC equipped with a flame ionization detector (FID) (Hewlett Packard 5890) following with the modification procedure of by Sun et al.32 The Agilent HP-FFAP capillary column (length = 25 m, i.d. = 0.2 mm, thickness = 0.3 μm) was used for analysis. The initial column temperature was settled at 100 ℃ for 0.5 min and raised at 15 ℃ min-1 to 200 ℃. The detector temperature was 260 ℃, while the injector temperature was 250 ℃. The helium was use as the carrier gas at the rate of 1 mL min-1 and splitless. The injection volume was 1μL. Every extraction was evaluated in triplicate and the results were expressed as g kg-1 of lyophilized weight (LW). The inhibition rate of acrylamide formation was computed:

Statistical analysis

The results reported are the average values. The Turkey’s honest significant difference (HSD) test with 95% confidence level was used to calculate the difference between the average values. The one-way analysis of variance (ANOVA) was used to evaluate the variations with Minitab 18 Statistical software (MINITAB Inc, State College, PA, USA). Pearson’s correlations analysis was used to analyze the relationships between the variables.

RESULTS AND DISCUSSION

Influence of phlorizin immersion concentration

Acrylamide formation

In this study, the effect of the phlorizin immersion concentration (0-0.30 g kg-1) prior to frying on the acrylamide formation of fried potato strips is shown in Fig. 1. The acrylamide levels of fried potato strips immersed at 40 ℃ for 60 min decreased as the phlorizin immersion concentration increased. It should be noted that the content of acrylamide in the fried potato strips significantly decreased from 8.01×10-3 to 2.23×10-3 g kg-1 LW and the inhibition rate of acrylamide formation greatly increased from 8.03% to 74.43% as the phlorizin immersion concentration increased from 0 to 0.14 g kg-1. However, the acrylamide content slightly decreased with the immersion concentration of phlorizin rising from 0.14 to 0.30 g kg-1 whose inhibition rate was exceeded to more than 70% and the content of acrylamide was lower than 2.50×10-3 g kg-1 LW. The inhibition rate (74.43%) of potato strips immersed at the phlorizin solution of 0.14 g kg-1 was higher than the rate of the strips immersed in sodium pyrophosphate of 10 g kg-1 that reported by Pedreschi et al.33 Therefore, the results showed that taking the cost into consideration during the industrial production, 0.14 g kg-1 could be used as the suitable immersion concentration of phlorizin of fried potato strips in the pretreatment, which dramatically reduced the acrylamide formation during frying. Negishi et al.34 reported that the extracts of plant could increase or decrease the acrylamide formation of frying potato strips. They could either protect the degradation of acrylamide or react with the intermediate precursors in the Maillard reaction to reduce the acrylamide formation at different stages through changing the kinetics of the chemistry and redirecting the chemical pathways.35 The phlorizin, extracted from apple, was determined to inhibit the acrylamide formation of frying potato strips which was likely due to trapping agents of reactive dicarbonyl species, such as methylglyoxal and glyoxal.36 Additionally, the liquid chromatography coupled with tandem mass spectrometry (LC/MS) and nuclear magnetic resonance (NMR) data proved that the key active sites were located at the C-3 or C-5 of A-ring, and the A-ring was more reactive than B-ring.15

Color parameters

The color values of fried potato strips with the phlorizin immersion before frying are shown in Table 1. Compared to the fried samples with water immersion before frying (phlorizin concentration of 0 g kg-1), the L* values with the phlorizin immersion of different concentration (from 0.04 to 0.18 g kg-1) tended to increase, which showed that the fried potato strips became lighter after the phlorizin immersion. The a* values significantly increased compared to the fried potato strips with the water immersion except the phlorizin solutions of 0.14, 0.16 and 0.18 g kg-1, which indicated that the fried potato strips got redder after the phlorizin immersion. However, the a* value of fried potato strips immersed with the phlorizin solution of 0.14 g kg-1 slightly changed compared to the fried potato strips with water immersion. The b* and C* value of fried potato strips with phlorizin immersion decreased and increased, respectively, compared to the water immersion except the phlorizin concentration of 0.04 g kg-1, while the H* value significantly decreased with the phlorizin concentration of 0.04, 0.08, 0.10, 0.18 mg /L, and slightly increased with the phlorizin solution of 0.14 and 0.16 g kg-1. Therefore, the fried potato strips with the phlorizin immersion of 0.14 g kg-1 tended lighter (L*), and the a*, b* and H* values were slightly changed compared to the color parameters of fried samples with water immersion. The results obtained also showed that 0.14 g kg-1 could be the suitable phlorizin immersion concentration for the fried potato strips prior to frying and improve the color properties of samples. The color parameters varied between the phlorizin and water immersion before frying as a result of the changing of precursors (such as reducing sugar and asparagine) in the Maillard reaction.3,33
The correlations between the color parameters and acrylamide content of fried potato strips with the immersion of different phlorizin concentrations were investigated. There was significant and negative correlation between L* and acrylamide content (r = -0.816, p < 0.01), while a*, b* and C* values were significantly and positively correlated with the acrylamide formation (r = 0.543, 0.631 and 0.668, p < 0.01, respectively), which was agreed with the reported with Yang et al.10 Textural profile parameters The textural changing of fried potato strips with different phlorizin immersion concentration is shown in Fig. 2. Compared to the textural values of fried potato strips with water immersion, the changing of hardness, springiness, cohesiveness and chewiness were not significant, which proved that the different immersion concentration of phlorizin didn’t dramatically affect the final textural values of fried potato strips. The correlations of texture, color and acrylamide formation of fried potato strips were analyzed. However, the significant correlation was only found between hardness and L* values (r = -0502, p < 0.05). Effect of Phlorizin immersion time Acrylamide formation To evaluate the influence of phlorizin immersion time on the acrylamide formation of fried potato strips, different immersion time (0-120 min) was studied with water immersion as the control group. As shown in Fig. 3, the acrylamide levels of fried potato strips immersed in the phlorizin immersion concentration of 0.14 g kg-1 at 40 ℃ changes varied with the immersion for 0-120 min. The acrylamide formation steadily reduced from 8.71×10-3 to 6.84×10-3 g kg-1 LW with the water immersion, and significantly decreased from 8.71×10-3 to 2.13×10-3 g kg-1 LW with the phlorizin immersion for 0-120 min. Compared to the fried samples without immersion (the immersion time of 0 min), the acrylamide levels with phlorizin immersion for 60 and 120 min reduced 74.43% and 75.60%, respectively, which indicated that the changing of acrylamide levels at the immersion time of 60 and 120 min was slight, and 60 min of phlorizin immersion could be selected to significantly reduce acrylamide formation in consideration of efficiency of the large-scale industrial processing. The water immersion reduced acrylamide content because the precursors of Maillard reaction were dissolved into water. The blanching processing with the asparagine enzyme could reduce about 80% of acrylamide content, but the cost of asparagine enzyme is high in the large-scale industry.37 In addition, Pedreschi et al.38 found that the blanching followed by the immersion of NaCl solutions could reduce the acrylamide content of potato slices in similar to 62%, and the blanching water made the NaCl diffusion in potato tissue easier to reduce the acrylamide content in frying. However, the traditional blanching temperature was 80-100 ℃, which may affect the potato sensorial properties.39 In this investigation, 60 min of phlorizin immersion could reduce about 75% of acrylamide content at 40 ℃, which could retain the majority of original sensorial properties. Color analysis The color values of fried potato strips with the phlorizin immersion concentration of 0.14 g kg-1 at 40 ℃ for different time are shown in Table 2. Increasing the immersion time from 0 to 120 min significantly increased the L* values of fried potato strips (p < 0.05), which suggests that the fried potato strips get more brightness. However, the increasing extent of L* values for the samples with water immersion was slight (p > 0.05).
The brightness of the surface of fried potatoes may be attributed to the decreasing of the precursor substances of Maillard reaction during the immersion process.40 The a* b* and C* values of fried potato strips decreased, and H* values significantly increased with the phlorizin immersion time from 0-120 min.
According to the obtained data, the correlations of fried potato samples immersed with different time (from 0 to 120 min) between the color parameters and acrylamide formation were calculated. The correlation between the L* value and acrylamide content was significant and negative (r = -0.710, p < 0.01), while the acrylamide formation presented the positive and significant correlations with a*, b*, C* and H* values (r = 0.906, 0.871, 0.863 and 0.498, p < 0.01, respectively) in agreement with a previous study on carrots.41 The correlations between the acrylamide formation and color parameters suggest that as the lightness of fried potato strips decreased and a*, b*, C* and H* increased, the acrylamide formation increased at the different phlorizin immersion time. Pedreschi et al.33 reported that getting darker of fried potato products was as result of Maillard reactions and the changing of other color parameters (a*, b*, C* and H*) was because of the Maillard non-enzymatic reactions. Textural profile analysis The texture parameter changes of fried potato strips with the phlorizin immersion concentration of 0.14 g kg-1 at 40 ℃ for 0-120 min are shown in Fig. 4. The hardness, springiness, cohesiveness and chewiness decreased as the phlorizin and water immersion time increased compared to the fried samples without immersion (immersion time of 0 min). The changing of texture parameters was attributed to the starch gelatinization and lamella media solubilisation during frying.42 In addition, we found that compared to the fried potato strips with water immersion, the texture parameter values of samples with phlorizin immersion at different time were higher and was closer to the values of fried samples without immersion. Considering the fried potato samples with the phlorizin immersion at different time, the acrylamide formation showed good correlations with hardness, springiness and cohesiveness (r = 0.492, 0.696 and 0.703, p < 0.05, respectively), but no significant correlation was found between the chewiness and acrylamide formation (r = 0.427, p > 0.05). Moreover, there were good correlations between texture and color parameters in the fried samples: L* values presented the negative and dramatical correlations with springiness and cohesiveness (r = -0.545 and -0.487, p < 0.01, respectively) which agreed with the report of Yang et al.40 ; a* values were positively and significantly correlated with springiness and cohesiveness (r = 0.701 and 0.611, p < 0.01, respectively); b* values showed the positive and significant correlations with hardness, springiness and cohesiveness (r = 0.547, 0.591 and 0.638, p < 0.05, respectively); C* values presented significant correlations with hardness, springiness and cohesiveness (r = 0.556, 0.612 and 0.588, p < 0.05, respectively); but no significant correlations were found between the chewiness and color parameters. Influence of phlorizin immersion temperature Acrylamide formation The acrylamide content of fried potato strips without immersion prior to frying was 8.63×10-3 g kg-1 LW. The acrylamide levels of fried potato strips prepared by the phlorizin immersion concentration of 0.14 g kg1 and the immersion time of 60 min at different temperature, with the water immersion as the control group, are shown in Fig. 5: the acrylamide content of samples with water immersion at the temperature from 20 to 50 ℃ ranged from 7.61×10-3 to 8.00×10-3 g kg-1 LW, and the inhibition rate was from 7.28 to 11.82% compared to the fried potato strips without immersion; the acrylamide content for the samples with phlorizin immersion was from 2.22×10-3 to 2.47×10-3 g kg-1 LW and the inhibition rate was from 71.39 to 74.32% which was dramatically higher than the inhibition rate of the report of Cheng et al.17 Cheng et al.17 studied the effect of citus flavonoid and naringenin on the formation of acrylamide and the inhibition rate of acrylamide formation was about 20-50% relative to the control. However, the changing of acrylamide contents with both phlorizin and water immersion was slight as the immersion temperature increased from 20 to 50 ℃, which suggests that the effect of the phlorizin immersion temperature on the acrylamide formation was not significant. Texture The texture parameters of fried potato strips with phlorizin and water immersion at the different temperature are shown in Fig. 6. Depending on the immersion temperature of phlorizin and water separately, the changing of hardness, springiness, cohesiveness and chewiness values of fried potato strips was slight, which means that the effect of the immersion temperature on the texture parameters was not significant (p > 0.05). Pearson correlations between the textural parameters and acrylamide content of fried potato strips immersed with the phlorizin solution at different temperature were also analyzed in our study. The springiness values showed the significant and negative correlations with the acrylamide formation of the samples with phlorizin immersion (r =-0.632, p < 0.05). However, other tested textural parameters showed no correlations with the acrylamide formation of fried samples with phlorizin immersion at different temperature, which is not consistent with several studies1,10 that reported significant correlations between the hardness and acrylamide contents of frying potato products. The mechanistic pathways of acrylamide formation and elimination of plant phenolics is complex and many phenomena are still confusing. These contrasting correlations may be due to trapping reactive dicarbonyl species, such as methylglyoxal and glyoxal, during the phlorizin immersion.36 Color In our study, surprising results were found for the fried potato samples with phlorizin immersion at the different temperatures compared to the fried samples without immersion (the control samples) (data no shown) (Table 3): the L* values of the fried samples with the phlorizin immersion at 20 ℃ were closer to the control samples (67.45 ± 1.28); the L* values for the fried samples immersed at 30, 40 and 50 ℃ were higher than the values of control samples. Additionally, the L* values tended to increase for the fried samples with both the water and phlorizin immersion as the immersion temperature increased, which means that the fried potato strips got lighter after immersion prior to frying, especially for the phlorizin immersion. The a* and b* parameters significantly decreased for the fried samples with both the water and phlorizin immersion as the immersion temperature increased, which indicated that the fried strips got less red and yellow, while the C* values tended to decrease and H* value increased (C* and H* values correlated with the parameters of a* and b*). The color parameter values obtained indicated the phlorizin immersion could improve the color properties of fried potato strips. The color parameters presented no significant correlations with the acrylamide content and textural parameters of fried potato strips immersed with phlorizin solution at different temperature (p > 0.05).

CONCLUSIONS

The pure phenolics and phenolic extracts have attracted a great deal of attention for its natural and safe feature to inhibit the acrylamide formation of fried potato products. The phlorizin was a very higher content of phenol compounds in apple fruit. The present work examined the effects of phlorizin immersion on acrylamide formation of fried potato strips with regards to the phlorizin immersion of concentration, time and temperature prior to frying. Overall, the acrylamide formation of fried potato strips significantly decreased as the phlorizin concentration increased from 0 to 0.14 g kg-1, while the acrylamide content slightly decreased with the concentration from 0.14 to 0.30 g kg-1. The phlorizin concentration of 0.14 g kg1 may be the suitable immersion concentration of fried potato strips in the pretreatment considering the cost. Additionally, compared to the fried samples without immersion, the acrylamide content of samples immersed with phlorizin solution at 60 and 120 min reduced 74.43 and 75.60% respectively, which indicated that 60 min of phlorizin immersion could be selected to significantly reduce the acrylamide formation in view of efficiency of the large-scale industrial processing. Moreover, the effect of the phlorizin immersion temperature on acrylamide formation was not significant. Specifically, the inhibition rate of acrylamide formation of fried potato strips immersed with phlorizin solution at the temperature of 20-50 ℃ was from 71.39 to 74.32% relative to the fried potato strips without immersion.
The fried potato strips immersed at the phlorizin solution got lighter with the phlorizin concentration from 0 to 0.18 g kg-1, the immersion time from 0 to 120 min, and the immersion temperature from 20 to 50 ℃, separately, which demonstrated that the phlorizin immersion before frying could improve the color properties of fried potato strips. Depending on the phlorizin immersion concentration and temperature separately, the changing of textural parameters of fried potato strips was slight. However, the textural profile values decreased as the phlorizin immersion time increased from 0-120 min.
Regarding the different phlorizin immersion concentration, time and temperature, the Pearson correlations demonstrated a significant relationship between the acrylamide formation and instrumental sensory properties in the fried potato strips. The instrumental sensory properties could be used as the indicator of acrylamide levels of fried potato strips during the industrial processing.

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