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发表于 2021-9-1 15:49 | 显示全部楼层 |阅读模式
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Journal|[J]Journal of Food Processing and PreservationVolume 45, Issue 3. 2021.
The impact of glucono delta‐lactone (GDL) on rice flour pasting properties and GDL’s dipping effects on the quality of rice noodles
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The impact of glucono delta‐lactone (GDL) on rice flour pasting properties and GDL’s dipping effects on the quality of rice noodles - Low - 2021 - Journal of Food Processing and Preservation - Wiley Online Library  

https://ifst.onlinelibrary.wiley.com/doi/10.1111/jfpp.14944
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发表于 2021-9-1 16:26 | 显示全部楼层
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The impact of glucono delta-lactone (GDL) on rice flour pasting properties and GDL’s dipping effects on the quality of rice noodles
Yan Kitt Low, Effarizah Mohd Esah, Lai Hoong Cheng
First published: 20 October 2020 https://doi.org/10.1111/jfpp.14944
South China Univ of Tech Open URL
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Abstract
In this study, fresh rice noodles were treated by glucono delta-lactone (GDL) dipping and in-pack pasteurization. Rice flour pasting analysis showed that the final viscosity and setback values increased with a progressive increase in GDL concentration, indicating that acid addition promotes rice gel retrogradation. This was substantiated by the texture profile analysis results, where the hardness value of the gel formed with GDL was harder than the control. It was found that when rice noodles were subjected to the treatments, the noodle strands were easily detached from one another. It is speculated that starch molecules present on the surface retrograded faster than those counterparts present in the core of the noodles strand. Thus, a dry protective layer might form to prevent the moisture migration. Desorption analysis results support this explanation, where treated noodles were found to show a higher moisture retention level and had a lower retrogradation index.

Practical applications
Fresh rice noodles have a short shelf life due to microbial risk and starch retrogradation. So, it is common that fresh rice noodles can only be made available in certain areas near the manufacturers. By dipping fresh rice noodles in an acidic glucono delta-lactone bath followed by in-pack pasteurization, the quality of noodles was dramatically improved. The treatment has successfully delayed the onset of long-term retrogradation of fresh rice noodles. These findings bring great benefits to the manufacturers as the distribution network of fresh rice noodles might be extended to both new and existing customers.

1 INTRODUCTION
Rice noodles have been a staple commodity from time immemorial for rice-producing countries like Thailand, Vietnam, China, and Malaysia and the consumption of fresh wet rice noodles has been a common practice in the aforesaid countries. The texture of fresh rice noodles has always turned harder and stickier upon storage due to starch retrogradation. As a result, it has been difficult to separate the noodles into individual strands for storage purposes. Therefore, fresh wet rice noodles are normally sold and consumed within a day or two upon production. In view of the high global demand for fresh rice noodles, shelf stable and convenient ready-to-use fresh rice noodles products are in very great demand.

The preservation of fresh noodles is challenging because the starchy nature of their structural network is susceptible to chemical attack and harsh physical treatments. Prolonging the shelf life of fresh noodles in terms of microbiological properties and textural stability is crucial. A few studies have been carried out on preserving fresh noodles especially the type that contains wheat using irradiation (Jianming, 1998; Li et al., 2011) and preservative agents (Huang et al., 2007; Klinmalai et al., 2017). Moreover, Rachtanapun and Tangnonthaphat (2011) modified the packaging condition and storage temperature of fresh rice noodles. However, the shelf life of the treated rice noodles was only 29 days with textural quality defects.

From literature studies, it can be said that acid dipping offers promising preservation effects to food products. Studies involving organic acid dipping in food products such as poultry (Arafa & Chen, 1978; Ariyapitipun et al., 1999; Jasass, 2008; Morshedy & Sallam, 2009), fish fillets (Bal'a & Marshall, 1998; Ingham, 1989), fruits (Salinas-Roca et al., 2016), and vegetables (Akbas & Ölmez, 2007; Hussain et al., 2014; Rahman et al., 2011) have been carried out by various researchers to reduce the microbial load. Acid dipping is an effective way of reducing the microbial population, but more often than not, the textural quality of acid-dipped food products during storage, has not been studied to a very great extent. Moreover, the effects of acid dipping on noodles product are yet to be found in our current literature search.

When glucono delta-lactone (GDL) is dissolved in water, it will produce gluconic acid. Its slow dissolution attribute makes it tastes less tart than other types of organic acids. GDL has been used as a coagulating agent in the making of tofu, as well as for cheese curd formation, and heat stability of milk in dairy industries. Kim et al. (2004) investigated the effects of GDL on cooked rice. It was found that the microbial and textural qualities of the cooked rice prepared with GDL and acetic acid above 0.1% concentration revealed a significant improvement. The hardness of the cooked rice prepared with both acidulants increased, indicating retrogradation happened faster with the presence of acids. The outcome of the study might be useful in predicting the textural qualities of rice-based noodles.

Moreover, the use of GDL in the noodles system was found to be reported in Japanese udon. This is a wheat-based product and is now marketed as a shelf stable product in supermarket. GDL is added into udon flour mix to provide a low pH system in order to prolong the shelf life of this wheat-based noodles (Sumitra et al., 2006). However, the direct addition of acid into the flour system might not be suitable for rice-based noodles. Acid hydrolysis occurred in the core of noodles due to acid attack that tends to weaken the structural integrity of the noodles because there is no gluten. As a result, the noodles produced are brittle and easily broken into short fragments, which is an undesirable trait. Acid dipping, moreover, may offer a better workability as the treatment is milder and limited to the outer surface of the noodle strands only.

It was hypothesized that when GDL solubilizes in water, a low pH system with mild tart flavor would be good for acid dipping of fresh rice noodles. More often if a combination of hurdles such as in-pack pasteurization is used, the safety of the packed rice noodles will be improved significantly. Moreover, the textural quality of the fresh rice noodles after having gone through the processes of acid dipping and in-pack pasteurization might change due to surface modifications because of the acid and heat treatments. The starch molecules on the surface of the noodle strand might experience partial hydrolysis and since more short chains of amylose are being freed, a higher intermolecular association will occur. The starch molecules re-sited on the surface is expected to retrograde faster than those counterparts re-sited in the core of the noodles strand. Thus, the retrograded outer part of the noodle strand might act as a barrier that keep the noodles apart and without sticking to each other. Thus, it can be hypothesized that GDL dipping coupled with in-pack pasteurization are able to promote the handling and textural properties of rice noodles for storage purposes.

In this study, the effects of GDL on the pasting and textural quality of rice flour and its gel quality were investigated. From the results, the modifications done by GDL on rice starch can be recognized and their interactions on noodles surface after being dipped in GDL solution can be predicted. Thus, commercial rice noodles were dipped in different concentration of GDL solution and subjected to further heat processing. The moisture desorption characteristic and the retrogradation index of the acid-dipped and in-pack pasteurized rice noodles were determined.

2 MATERIALS AND METHODS
2.1 Materials
The commercial Erawan branded rice flour (30% amylose content based on total carbohydrate) from Tiga Gajah Cho Heng Sdn. Bhd. (Penang, Malaysia) used in this study was purchased from the local hypermarket (Tesco Extra, Penang, Malaysia). Food-grade GDL powder and commercial rice noodles were purchased from Euro Chemo-Pharma Sdn. Bhd. (Penang, Malaysia) and HSB Laksa Marketing Sdn Bhd. (Penang, Malaysia), respectively.

2.2 Preparation of GDL solution and pH analysis
GDL solutions at different concentrations (0.05%, 0.1%, 0.5%, 1.0%, and 1.5% w/v) were prepared. To prepare 1,000 ml of 1.0% GDL solution, 10 g of GDL powder was dissolved in distilled water using a 1,000 ml volumetric flask. The GDL solutions prepared were left overnight before use and the pH value was determined using a pH meter (Eutech Instruments pH 510, Singapore).

2.3 RVA pasting properties of rice flour
The effects of GDL solution concentrations (0.05%, 0.1%, 0.5%, 1.0%, and 1.5% w/v) on the pasting properties of commercial rice flours were determined using a Newport Scientific Rapid Visco Analyser with a standard method of the AACC. Distilled water (25 ± 0.1 ml) and rice flour (3.0 g) were weighed into an aluminum canister. The moisture content of the rice flour was corrected to 14%. The slurry formed was jogged up and down vigorously using a plastic paddle before being loaded onto the instrument. The flour slurry was sheared at 160 rpm and undergone heating from 25 to 90°C followed by a holding at 90°C for 4 min and then, cooled to 50°C. The attributes recorded were peak viscosity, trough viscosity, pasting temperature, breakdown viscosity, final viscosity (FV), and setback (SB) viscosity. For GDL-treated samples, GDL solution was used instead of distilled water. Analyses were replicated thrice.

2.4 Texture profile analysis of rice flour gel
Starch paste produced from the RVA analysis was transferred into a syringe of an internal diameter of 14.3 mm, sealed with parafilm to prevent the moisture loss and left overnight (24 hr) at room temperature (30°C) to allow retrogradation to occur. Upon storage, the cylindrical-shaped extruded starch gel was cut into a 2 cm long rod for compression study. The TPA of the gel was studied using a Texture Analyzer (TA-XT Plus, Texture Technologies/Stable Micro System, Surrey, UK) equipped with a 5 kg load cell and a 36 mm cylindrical probe with a test speed and post-test speed of 5.0 mm/s. The test was done by compressing the starch gel twice on the platform until the deformation reached 75% strain. From the force–time curve of the TPA, textural parameters including hardness, adhesiveness, springiness, cohesiveness, chewiness, and resilience were obtained. This TPA was replicated with eight sub-samples.

2.5 Moisture desorption analysis of acid-dipped rice noodles
Commercial rice noodle strands were dipped in different concentrations of GDL solutions (0.05%, 0.1%, 0.5%, 1.0%, and 1.5% w/v) for 2 min before in-pack pasteurization was carried out which the noodles were vacuum packed in nylon pouch; these 150 g pouches were subjected to mild heat treatments (62°C/1 hr). The treated and nontreated noodle strands samples (water activity of 0.99) were placed in a moisture dish and the initial weight of the dish with the lid on was recorded. The uncovered dish was then placed in a desiccator over phosphorus pentoxide. Weight changes of all samples were monitored over a storage period of 72 hr. The moisture content of the noodles was calculated using the following equation:
urn:x-wiley:01458892:media:jfpp14944:jfpp14944-math-0001
where, W1 g is weight of moisture dish + lid, W2 g is weight of moisture dish + lid + sample (before drying), and W3 g, is weight of moisture dish + lid + sample (after drying).

2.6 Retrogradation index determination of acid-dipped rice noodles
Samples used to determine the retrogradation index were treated the same as those prepared for moisture desorption analysis. The noodle packs were stored at room temperature (30°C) and tested for day 0, week 2, 4, 8, and 12. The changes in hardness of the noodle strands were evaluated using a Texture Analyzer (TA-XT Plus, Texture Technologies/Stable Micro System, Surrey, UK) equipped with a 5 kg load cell and a 36 mm cylindrical probe with a test speed and post-test speed of 5.0 mm/s. The test was done by compressing the noodle strands on the platform until the deformation reached 75% strain. The test was repeated eight times. From the force–time curve of the TPA, the textural parameter of hardness was determined. The retrogradation index was calculated using the following equation.
urn:x-wiley:01458892:media:jfpp14944:jfpp14944-math-0002
where, Hn is hardness of rice noodles on day n, and H0 is hardness of rice noodles on day 0.

3 RESULTS AND DISCUSSION
3.1 pH analysis
All pH values of the GDL solutions prepared have been tabulated in Table 1. As the concentration of GDL solution increases from 0.05% to 1.50%, pH values decrease from 3.12 to 2.39. These values fall within a pH range commonly set for acid dipping purposes, which is below 4.6. It is an accepted fact that for food items intended to be stored without refrigeration or are to undergo mild heat treatment, proper acidifying of pH to 4.6 or below will help to inhibit growth and toxin formation especially from bacteria causing botulism. Compared to the work reported in US Patent 5695801A (Oh, 1997), where citric acid and lactic acid were used in combination, the amount of acidulants needed for preparing an acid bath, was much lower when GDL is used. As reported, a concentration as high as 2% to 4% was required to prepare a citric–lactic acid bath with pH value in the range of 1.5 to 3.5. With GDL, concentration at 0.05% already reaches pH value of 3.12.

TABLE 1. pH values of GDL solutions of different concentrations
GDL concentration (w/v %)        pH value
0.05        3.12 ± 0.06e
0.10        2.92 ± 0.01d
0.50        2.63 ± 0.01c
1.00        2.51 ± 0.03b
1.50        2.39 ± 0.01a
Note
Mean ± standard deviation (n = 3) values with different superscript letters differ significantly (p < .05).
Abbreviation: GDL, glucono delta-lactone.
Moreover, it has been found that GDL could be a better acidulant of choice since GDL solutions do not taste as tart as other acidulants. According to Sumitra et al. (2006), GDL has a slower releasing rate when it dissolves in water, thus producing an initial sweet taste that slowly turns acidic. This is advantageous when GDL is used to treat bland taste rice noodles. The GDL solution absorbed during the acid dipping process would be enough to effect preservation but not high enough to alter the taste of the rice noodles. Furthermore, the residual portion of the GDL which remained on the surface of the noodles could be washed out via a parboiling or blanching process at the point of cooking. This would make the GDL-treated rice noodles taste indistinguishably from the control rice noodles.

3.2 Pasting analysis
The process of starch granules gelatinization starts with granular swelling, followed by exudation of molecular constituents through the total disruption of the starch granules. The whole process is known as pasting (Meadows, 2002). Pasting properties of starch varies as they depend on various factors such as amylose–amylopectin content and molecular properties, lipid content, starch type, and their respective genotypic diversities (Bao et al., 2006).

The typical RVA viscograms of rice flour samples treated with different concentrations of GDL solution are shown in Figure 1. An overview from Figure 1 shows that rice flour pasting properties were modified substantially with the addition of GDL into the slurry. The control rice flour slurry was pasted with low peak viscosity and low breakdown values. On cooling, a rise in viscosity was evident with FV recorded at a viscosity value much higher than the corresponding peak viscosity. Upon addition of GDL, the rice flour slurries’ peak viscosity generally shifted to a much higher value and resulted in a larger breakdown value. However, the FV increased marginally with increase in GDL concentration to a threshold value and then, dropped progressively. Briefly, the pasting profile of the GDL-treated rice flour mimicking those of potato starch.

image
FIGURE 1
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The typical RVA viscograms of rice flour suspension pasted with different concentrations of GDL solution
Table 2 tabulates in greater detail, the pasting parameters of all samples studied as a function of GDL concentration. All the parameters of pasting properties of the rice flour treated with the GDL solution were significantly different from the control sample (p < .05). Generally, the pasting temperature decreased with a progressive increase in GDL concentration and the reverse trend was observed in peak viscosity and breakdown viscosity. As for trough viscosity, FV, and SB viscosity, the respective viscosity values increased with the increase in GDL concentration to a threshold value of 0.1% and the viscosity values dropped with a further increase in GDL concentration.

TABLE 2. Pasting properties of rice flour suspension pasted with different concentrations of GDL solution
GDL concentration (w/v %)        Pasting temperature (°C)        Peak viscosity (cP)        Trough viscosity (cP)        Breakdown (cP)        Final viscosity (cP)        Setback (cP)
0.00        91.37 ± 0.75d        1,558 ± 30a        1,515 ± 29a        43 ± 1a        3,029 ± 57a        1,514 ± 28a
0.05        90.42 ± 0.65cd        1,817 ± 22b        1,800 ± 18c        17 ± 5a        3,690 ± 10c        1,890 ± 9b
0.10        89.32 ± 0.40c        2,220 ± 17c        2,101 ± 11e        119 ± 6b        4,538 ± 29e        2,436 ± 22e
0.50        86.92 ± 0.33b        3,531 ± 30d        2,128 ± 33e        1,403 ± 4c        4,430 ± 36e        2,302 ± 4d
1.00        83.62 ± 0.40a        4,109 ± 31e        1,908 ± 22d        2,201 ± 22d        3,983 ± 28d        2,074 ± 11c
1.50        82.32 ± 0.60a        4,378 ± 29f        1,693 ± 3b        2,689 ± 36e        3,550 ± 3b        1,857 ± 6b
Note
Mean ± standard deviation (n = 3) values with different superscript letters in the same column differ significantly (p < .05).
Abbreviation: GDL, glucono delta-lactone.
These observations could be attributed to the acid thinning effects caused by GDL on rice starch granules. In the presence of weak acid, starch granules could have been partially hydrolyzed. Inevitably, the amorphous domain which is mainly made up of amylose molecules would be more prone to acid hydrolysis than the crystalline counterpart of amylopectin. As a result, upon the addition of GDL, pasting occurred at a relatively lower temperature because it is much easier to leach out the partially hydrolyzed amylose from the swollen granules (Sandhu et al., 2007).

Moreover, peak viscosity is associated with the maximum swelling capacity of the starch granules before they are physically ruptured (Corke et al., 1997). The result obtained may suggest that the leached-out amylose molecules present in the continuous phase of starch suspension could have created a cushioning effect to facilitate or enhance the swelling capacity of the starch granules (Tester & Morrison, 1990; Yoshimura et al., 1998). This denotes that the addition of GDL to rice flour would induce a higher viscous load to the starch suspension during the cooking process.

Since breakdown is calculated as the difference between the peak viscosity and the trough viscosity, as the peak viscosity escalated at a much faster rate than the increase in the trough viscosity, breakdown viscosity increased exponentially in response to the increase in GDL concentration.

The partial hydrolysis effects caused by GDL solution had been carried over to trough viscosity, FV, and SB viscosity. As more short chains amylose molecules were freed from the starch granules, a higher intermolecular association or interaction was expected. This explains the increase in trough viscosity, FV, and SB viscosity when GDL concentration is increased from 0% to 0.1%. The decrease in trough viscosity, FV, and SB viscosity after 0.1% GDL could be attributed to the possibility of having insufficient or limited chain length of amylose molecules to promote intermolecular interactions due to excessive hydrolysis caused by GDL (Wurzburg, 2006). These results are in accordance with the findings of Jyothi et al. (2005), who reported similar result trends on cassava starch with acetic acid; however the critical threshold happened around 0.5%. This observation indicates that the starch molecules present on the surface of rice noodles strand may experience enhanced retrogradation if they are mildly treated with GDL during the acid dipping process.

3.3 Texture profile analysis of rice flour gel
Table 3 shows the TPA parameters of all the rice flour gel samples studied. It is found that hardness values of the rice flour gel samples increase with the progressive increase in GDL concentration up to 0.5% and followed by a plateau wherein insignificant differences between hardness values were recorded for samples added with 0.5%, 1.0%, and 1.5% GDL. An almost similar trend is observed for cohesiveness, chewiness, and resilience parameters. Since, all these parameters are associated with the network strength of the starch gel formed, one can deduce that GDL treatment has promoted the intermolecular interactions and produced a firm, cohesive, chewy, and elastic gel. The former RVA findings have substantiated this result where enhanced intermolecular interactions were evident in the trough viscosity, FV, and SB viscosity when GDL was added to the rice flour slurry. Interestingly, the relatively weaker intermolecular interaction showed by the rice flour paste added with 1.5% GDL was not manifested in this TPA.

TABLE 3. Texture profile analysis parameters of rice flour gel prepared with different concentrations of GDL solution
GDL concentration (w/v %)        Hardness (g)        Adhesiveness (g.s)        Springiness        Cohesiveness        Chewiness        Resilience
0        231.52 ± 22.87a        −44.02 ± 7.79c        0.45 ± 0.06a        0.31 ± 0.02a        33.07 ± 8.22a        0.07 ± 0.01a
0.05        239.43 ± 10.25a        −90.18 ± 22.19b        0.82 ± 0.07b        0.42 ± 0.02b        81.44 ± 11.06b        0.07 ± 0.00a
0.1        310.05 ± 23.45b        −129.82 ± 13.00a        0.86 ± 0.00b        0.46 ± 0.01c        121.22 ± 10.28c        0.08 ± 0.01b
0.5        371.24 ± 13.10d        −120.58 ± 5.75a        0.83 ± 0.01b        0.51 ± 0.02d        156.24 ± 10.54e        0.12 ± 0.01c
1.0        329.11 ± 18.82bc        −102.45 ± 7.80b        0.81 ± 0.01b        0.52 ± 0.02d        138.67 ± 8.78d        0.13 ± 0.01d
1.5        346.88 ± 19.10cd        −98.89 ± 5.65b        0.82 ± 0.00b        0.52 ± 0.01d        147.46 ± 6.47de        0.13 ± 0.00d
Note
Mean ± standard deviation (n = 8) values with different superscript letters in the same column differ significantly (p < .05).
Abbreviation: GDL, glucono delta-lactone.
Adhesiveness in its negative value indicates the force area under the first compression. It is a workforce required to overcome the attractive force between the food surface and the material that contacts with the food (Kasapis, 2009). Data obtained shows that the adhesiveness value increased from the control sample through sample added with 0.1% GDL concentration. Further addition of GDL concentration resulted in a slight decrease in adhesiveness. Higher adhesiveness values may suggest a higher time dependency for the rice gel to recover back to its original consistency upon deformation. As a result, after being deformed the disrupted gel network adheres to the platform and probe. This higher adhesiveness value reflects also a moist attribute perceived when the gel is consumed.

The results show that all GDL added starch gel samples possess a significant higher springiness value than the control sample, but no significant difference was shown between the treated samples. Springiness indicates the elasticity of a sample and how well it physically bounces back after the first bite. Therefore, the higher the springiness values, the more mastication the food may require.

As a whole, TPA analysis reveals that when a small amount of GDL is added (0.05% and 0.1%), the textural qualities of the starch gels improved significantly, but the modification become less prominent when a higher amount of GDL concentration (0.5%, 1.0%, and 1.5%) is used. Thus, in the context of fresh rice noodles, mild GDL treatment at a 0.5% concentration level during the acid dipping process may be appropriate in achieving preservation effects without compromising the textural qualities.

3.4 Moisture desorption analysis
Moisture desorption data (Figure 2) of the samples studied are illustrated by plotting the equilibrium moisture content reached as a function of storage time. The general coefficient of variance of the data points are less than 15%. From Figure 2, the equilibrium moisture content of the control sample (non-acid dipped) has the lowest values over the storage days, indicating that the control rice noodles easily lost their moisture to the drier headspace prevailed in the desiccator. However, the equilibrium moisture content of the GDL-treated rice noodles were significantly higher than the control samples. Figure 3 clearly shows that the control samples became dehydrated after 72 hr of storage, while the GDL-dipped samples remained moist. This indicates that when noodles are treated by dipping them in the GDL bath, rice noodle strands can retain a relatively higher moisture content when compared to the control sample. One plausible explanation for this observation is this: the GDL-treated starch molecules present on the surface of the rice noodle strands could have interacted to form a protective layer to prevent moisture loss to the environment. This speculation is supported by the findings reported previously in the pasting analysis and TPA.

image
FIGURE 2
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The moisture desorption analysis graph of rice noodles dipped in different concentrations of GDL solution. The general coefficient of variance of data points are <15%
image
FIGURE 3
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The treated (left) and non-treated (right) noodles samples after 72 hr storage in a desiccator
3.5 Retrogradation index of acid-dipped rice noodles
Retrogradation refers to the phenomenon that happens when amylose and amylopectin chains in a cooked and gelatinized starch realign into an ordered structure upon cooling (Wang et al., 2015). Amylose retrogradation takes place right after the gelatinized starch paste is cooled down and amylopectin retrogradation happens much later, thus they are known as short-term and long-term retrogradation, respectively. Very often, the onset of starch retrogradation serves as a shelf life indicator where starch-based foods start showing the signs of quality deterioration such as staling or hardening and syneresis. As for rice noodles, retrogradation is undesirable because the noodle strands will become hard and labile and will break easily upon retrogradation. The moisture leached during retrogradation made the noodle strands sticky and they tended to form a block that was hard; that made storage difficult.

Figure 4 depicts the changes in the retrogradation index of the rice noodles studied over a storage period of 12 weeks. The general coefficient of variance of the data points are less than 15%. The results of samples treated with 0.5% GDL have been omitted in this experiment due to unintentional human errors. In the early stage of storage (0–2 weeks), all samples retrograded at a faster pace (as shown by the steeper slope) than those which occurred at the later stage of storage. For long-term retrogradation, the retrogradation index of GDL-treated rice noodles decreases when the GDL solution concentrations decrease in the order of 0.05% > 0% > 0.1% > 1.0% > 1.5%. This result is indicative that acid dipping in GDL solution and its progressive increase in concentration helps to delay the onset of long-term retrogradation of treated rice noodles.

image
FIGURE 4
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Retrogradation index of acid dipped rice noodles during storage. The general coefficient of variance of data points are <15%
The above observation substantiates the findings reported in the previous sections. It is surmised that upon GDL dipping, the starch molecules re-site on the surface of the noodle strands could have retrograded and formed a protective layer surrounding the noodle strands that helps to prevent the moisture lost. The retained water molecules may in turn help to delay retrogradation and make the noodle strands softer. The abnormal result trend showed by 0.05% is unsolved at this moment.

4 CONCLUSION
GDL has been proven to be a promising additive used to modify the rice flour pasting properties and the gel quality made therefrom. Inevitably, dipping fresh rice noodles in a GDL solution followed by treating it with mild heat treatment were found to be efficacious in overcoming the textural issue arose during storage.

ACKNOWLEDGMENTS
Low Yan Kitt is thankful to MSM Malaysia Holding Bhd and Kuok Foundation for the financial assistance and supports through Malayan Sugar Manufacturing (MSM) Fellowship.

CONFLICT OF INTEREST
The authors would like to declare that there is no conflict of interest in this subject matter.
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Leon363 发表于 2021-9-1 16:01
The impact of glucono delta‐lactone (GDL) on rice flour pasting properties and GDL’s dipping effec ...

  可以看全文啊
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发表于 2021-9-1 16:27 | 显示全部楼层
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  红包给2楼的吧
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发表于 2021-9-1 16:35 | 显示全部楼层
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许老师您有账号登陆吧?我是游客状态只能付费看
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发表于 2021-9-1 16:37 | 显示全部楼层
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Leon363 发表于 2021-9-1 16:35
许老师您有账号登陆吧?我是游客状态只能付费看

  可能我们学校买啦
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发表于 2021-9-1 16:42 | 显示全部楼层
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xilinxu 发表于 2021-9-1 16:37
可能我们学校买啦

应该是咯,走出校园以后想查些文献都费老大劲
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 楼主| 发表于 2021-9-1 16:52 | 显示全部楼层
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谢谢大家!我已通过别的渠道下载到全文。现在发到上面,供大家分享!

葡萄糖酸内酯( GDL )对米粉糊化特性的影响及GDL浸渍对米粉品质的影响.14944.pdf

466.49 KB, 下载次数: 2, 下载积分: 粮票 -1

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 楼主| 发表于 2021-9-1 17:03 | 显示全部楼层
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 楼主| 发表于 2021-9-1 17:04 | 显示全部楼层
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特别感谢许老师的帮助!请许老师加我VX,兑现承诺的红包。
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食品论坛版主勋章2009年度魅力人物2012年度魅力人物2013年度魅力人物终身魅力人物食坛传奇勋章爱心勋章特约评论员认证会员

发表于 2021-9-2 00:53 | 显示全部楼层
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fuxiaoru6666 发表于 2021-9-1 17:03
特别感谢许老师的帮助!请许老师加我微信,兑现承诺的红包。

  有心就行啦
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