scholarly journals Pengaruh Penambahan Asam Sitrat Terhadap Proses Non-Enzimatik Browning Jus Buah Pir Yali (Pyrus bretschneideri Rehd.)

2020 ◽  
Vol 18 (3) ◽  
pp. 186
Author(s):  
Victoria Agatha Angela Sirait ◽  
Zulkifli Zulkifli ◽  
Tundjung Tripeni Handayani ◽  
Martha Lulus Lande

The purpose of this study was to find out how effective citric acid is against the nonenzymaticprocess of browning Yali Pear fruit juice (Pyrus bretschneideri Rehd. Theresearch was conducted in a complete randomized design consisting of 5 replications. Thenon-enzymatic browning inhibition process was tested with citric acid treatment as the mainfactor with five concentrations ie 0% w/v, 2,5% w/v, 5% w/v, 7,5% w/v and 10% w/v.Qualitative parameters were dehydrogenase enzyme activity and reducing sugar level.Quantitative parameters were browning index and total soluble carbohydrate content.Levene test, analysis of variance, and Tukey test were performed at 5% significant level. Theresults showed that decrease in dehydrogenase enzyme activity occurs along with increasingthe concentration of citric acid. The level of reducing sugar has increased along with theincrease of citric acid concentration. The 7,5% w/v citric acid concentration effectivelyinhibited non-enzymatic browning of Yali Pear juice with a 21% reduction in the browningindex. Total soluble carbohydrate content increased 7% at 7.5% w/v citric acidconcentration. From the results of the study it was concluded that citric acid at 7,5% w / vconcentration was the inhibitor of non-enzymatic browning and dehydrogenase enzymeactivity, but stimulator of total soluble carbohydrate and reducing sugar level.

2017 ◽  
Vol 17 (2) ◽  
Author(s):  
Oktarina Husaini ◽  
Zulkifli Zulkifli ◽  
Martha L. Lande ◽  
E. Nurcahyani

The purpose of this study was to prove that the water extract of guava pulp can hinder the process of browning in apples Malang. The research was conducted in October - November 2016 in the Laboratory of Plant Physiology, Department of Biology, Faculty of Mathematics and Natural Sciences, University of Lampung. This study uses a completely randomized design (CRD) with 6 degree of concentration of water extract of the fruit flesh guava: control (Citric acid 2% w/v), 0% v/v, 25% v/v, 50% v/v, 75 % v/v, 100% v/v. Browning index is determined based on the absorbance of the extract of apple Malang at a wavelength of 420 nm. Total soluble carbohydrate content was determined by the phenol-sulfuric method, while estimating dehydrogenase enzyme activity by methylene blue method. Levene's test for homogeneity, analysis of variance and LSD test was carried out at 5% significance level. Water extract of guava fruit has the same effectiveness with citric acid 2% w/v in inhibiting browning apples Malang. Similarly, the water extract of guava fruit as well as citric acid 2% w/v has the same effect on total soluble carbohydrate content and the activity of the enzyme dehydrogenase. Water extract of guava fruit has the same effectiveness with citric acid 2% w/v except for 100% concentration on reducing sugar level. The final conclusion is that the water extract of guava fruit has the different characteristics as citric acid 2% w/v in inhibiting browning in apples Malang. Keywords: water extract of guava fruit, browning index, total soluble carbohydrate content, dehydrogenase enzyme activity.


2017 ◽  
Vol 17 (1) ◽  
Author(s):  
Rizka Devi Anggita ◽  
Zulkifli Zulkifli ◽  
Martha L Lande

The purpose of this study was to determine the effect of water extract of pineapple shell in the process of browning apple manalagi  (Malus sylvestris Mill). The research was conducted from October to November 2016 in the Laboratory of Plant Physiology Department of Biology, Faculty of Mathematics and Natural Sciences, University of Lampung. As variables were browning index, total soluble carbohydrate content, dehydrogenase enzyme activity, and reducing sugar levels, while the parameter is the mean of all variables. The experiment was conducted in completely randomizes design. The main factor was the water extract of the  pineapple shell with 5 concentration levels:  0% v / v, 25% v / v, 50% v / v, 75% v / v, 100% v / v. Levene test, analysis of variance and LSD test was carried out at 5% significance level. The results showed that the water extract pineapple shell was significantly lower the browning index of apples manalagi, and the relationship between the concentration and browning index is quadratic (y = 9E-05x2 - 0.013x + 1.018 R² = 0665). Extract of pineapple shell did not significantly affect total soluble carbohydrate content of apples manalagi but a downward  trend in total soluble carbohydrate content with increasing concentrations of the extract (y = -0.049x + 29.66   R² = 0.923). The relationship between the concentration of water extract pineapple shell with dehydrogenase enzyme activity was negative linear (y = -0.082x + 12.04   R² = 0.969). Reducing sugar levels increase at the concentration of 50% v/v,75% v/v, and 100% v/v. The final conclusion was that the water extract of pineapple shell was potential as anti-browning agent for apples manalagi because it was able to reduce browning index 51.89%, and influence other physiological processes.Keywords: Pineapple shell, Apples manalagi, Browning, carbohydrate, dehydrogenase.


Inventions ◽  
2021 ◽  
Vol 6 (3) ◽  
pp. 50
Author(s):  
Silvia Lazăr (Mistrianu) ◽  
Oana Emilia Constantin ◽  
Nicoleta Stănciuc ◽  
Iuliana Aprodu ◽  
Constantin Croitoru ◽  
...  

(1) Background: This study is designed to extract the bioactive compounds from beetroot peel for future use in the food industry. (2) Methods: Spectrophotometry techniques analyzed the effect of conventional solvent extraction on betalains and polyphenolic compounds from beetroot peels. Several treatments by varying for factors (ethanol and citric acid concentration, temperature, and time) were applied to the beetroot peel samples. A Central Composite Design (CCD) has been used to investigate the effect of the extraction parameters on the extraction steps and optimize the betalains and total polyphenols extraction from beetroot. A quadratic model was suggested for all the parameters analyzed and used. (3) Results: The maximum and minimum variables investigated in the experimental plan in the coded form are citric acid concentration (0.10–1.5%), ethanol concentration (10–50%), operating temperature (20–60 °C), and extraction time (15–50 min). The experimental design revealed variation in betalain content ranging from 0.29 to 1.44 mg/g DW, and the yield of polyphenolic varied from 1.64 to 2.74 mg/g DW. The optimized conditions for the maximum recovery of betalains and phenols were citric acid concentration 1.5%, ethanol concentration 50%, temperature 52.52 °C, and extraction time 49.9 min. (4) Conclusions: Overall, it can be noted that the extraction process can be improved by adjusting operating variables in order to maximize the model responses.


Author(s):  
Juliana Zanol Merck ◽  
Camila Suliani Raota ◽  
Jocelei Duarte ◽  
Camila Baldasso ◽  
Janaina Da Silva Crespo ◽  
...  

The pollution of hydric sources by pharmaceuticals is an issue in many countries, particularly in Brazil. The presence of these substances causes deleterious effects on the environment and human health. One of the main sources of this contamination is domestic sewage, due to the expressive amount of medicines released in their unaltered form. Unfortunately, traditional wastewater treatment is not effective for the removal of pharmaceuticals and, for this reason, membrane technology is an attractive alternative to overcome this issue. In this regard, hydrophilic polymers, such as poly(vinyl alcohol) (PVA), are the most suitable. However, their high affinity with water causes intense swelling, leading to severe modifications in the membrane properties. In view of all these facts, the present work evaluated the swelling of PVA-based membranes, with the aim of finding the membrane preparation method that has the lowest swelling, thereby providing the most suitable characteristics for pharmaceutical removal from wastewater. The membranes were prepared by the casting of a polymeric solution, with PVA as a basis polymer, citric acid as a crosslink agent and glycerol and silver nanoparticles as performance additives. The process optimization was performed using a design of experiments with posterior analysis by the response surface methodology (RSM). The RSM assessed the effect on the membrane swelling of the factors, including citric acid concentration and the time and temperature of crosslinking. The membrane characterization was performed by Fourier-transform infrared (FT-IR) spectroscopy, scanning electron microscopy coupled with a field emission gun (SEM-FEG) and water contact angle (WCA) measurements. Overall, the condition that showed the lowest swelling was obtained with 10% of citric acid and crosslinking for 4 h at 130 °C. Under these conditions, the membrane had a mass swelling of 42% and a dimensional swelling of 24%. Additionally, our statistical analysis revealed that the factors with the dominant effects were the citric acid concentration and the temperature of crosslinking. The FT-IR analysis suggested that the crosslinking occurred by an esterification reaction, as showed by the stretching frequencies of C=O at 1710 cm-1 and ester C-O at 1230 cm-1. Moreover, the SEM-FEG images revealed a smooth and flat surface and a dense cross section with a thickness of ~113 μm. Concerning the WCA, the angle was at ~80°, which is characteristic of hydrophilic materials. Finally, the data suggested that it is possible to optimize the membrane preparation process with adequate properties so that it can be subsequently applied to the removal of pharmaceuticals from hospital wastewater.


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