scholarly journals Survey on Methods for Investigating Protein Functionality and Related Molecular Characteristics

Foods ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 2848
Author(s):  
Yuqi Zhang ◽  
Siddharth Sharan ◽  
Åsmund Rinnan ◽  
Vibeke Orlien

Proteins from various sources are widely used in the food industry due to their unique functional performances in food products. The functional properties of proteins are somehow dictated by their molecular characteristics, but the exact relationship is not fully understood. This review gives a tangible overview of the methods currently available for determining protein functionality and related molecular characteristics in order to support further research on protein ingredients. The measurements of protein functionality include solubility, water holding capacity, oil holding capacity, emulsion property, foam property, and gelation. This review also provides a description of different methods of molecular characteristics including electrophoresis, surface hydrophobicity and charge, molecular interaction, and thermal property measurement. Additionally, we have put significant emphasis on spectroscopic methods (ultraviolet-visible, Fourier transform infrared, Raman, circular dichroism, fluorescence and nuclear magnetic resonance). In conclusion, first and foremost, there is a need to agree on a standardization of the analytical methods for assessing functional properties. Moreover, it is mandatory to couple different analyses of molecular characteristics to measure and monitor the structural changes obtained by different processing methods in order to gain knowledge about the relationship with functionality. Ideally, a toolbox of protein analytical methods to measure molecular characteristics and functionality should be established to be used in a strategic design of protein ingredients.

2009 ◽  
Vol 15 (5) ◽  
pp. 453-463 ◽  
Author(s):  
C. Radha ◽  
V. Prakash

Heat processing of soybeans alters its structural behavior, solubility, and in turn the functional properties. Heat-processed soy flour was prepared by autoclaving the defatted soy flour at 121 °C at 15 psi. The effect of enzymatic modification on the structural changes and functional properties of heat-processed soy flour was investigated. The combination of heat processing and enzymatic modification was carried out in two ways: (1) enzymatic modification followed by autoclaving and (2) autoclaving followed by enzymatic modification. Defatted soy flour (control), autoclaved soy flour, enzyme-modified flour, enzyme-modified and then autoclaved flour, autoclaved and then enzyme-modified flour were analyzed for physico-chemical and functional properties. Molecular weight profile of the protein was altered depending on the nature of treatments. Structural studies showed that enzymatic modification gave a porous type morphology to the particles. Enzymatic modification of autoclaved soy flour increased its surface hydrophobicity to 3136±400 units from 600±100 units of autoclaved soy flour. The results indicated that enzymatic modification of autoclaved soy flour increased its acid solubility (pH 4—4.5) from 17% to 56% over a control value of 24%. The foaming capacity of the enzyme-modified and then autoclaved soy flour was 80% while that of the autoclaved and then enzyme-modified flour was 42%. The soy flour that was autoclaved and then enzyme modified showed better emulsifying properties (174 mL oil/g flour) than the flour that was enzyme-modified and then autoclaved. The modified soy flour based on its functional and physico-chemical properties should find application in many food systems.


1995 ◽  
Vol 31 (11) ◽  
pp. 153-158 ◽  
Author(s):  
M. Kajino ◽  
K. Sakamoto

Musty odor has occurred annually in Lake Biwa since 1969. Osaka municipal waterworks, which is located downstream of Lake Biwa, has made many efforts to treat musty-odor compounds produced in Lake Biwa from spring through autumn. With the development of analytical methods for the determination of musty-odor compounds, we have been able to confirm that planktonic blue-green algae are the major causes of the musty-odor occurrences. The relationship between the growth of blue-green algae and the water quality was not so apparent. However, through our data analysis focusing on the relationship between musty-odor occurrences due to Phormidium tenue or Oscillatoria tenuis and some nutrients in Lake Biwa, we found that the concentration of nitrate in water may be an important parameter for the estimation of growth of the algae and the musty-odor behavior.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Passakorn Kingwascharapong ◽  
Manat Chaijan ◽  
Supatra Karnjanapratum

AbstractImpact of ultrasound-assisted process (UAP) on yield, functional properties, antioxidant properties and molecular characteristics of protein extracted from Bombay locusts (BL) (Patanga succinta L.) was studied. Different conditions of UAP were implemented for different amplitudes (40–60%) and times (10–30 min) during aqueous extraction. Notably, UAP could enhance yield and protein recovery, compared with those from typical process (TP) (continuously stirred at 100 rpm at room temperature for 1 h). UAP conditions used governed the change of surface hydrophobicity and free α-amino content of BL. UAP could improve solubility of BL, especially at pH levels higher than 2. UAP had no significant (p > 0.05) detrimental effects on foaming capacity and stability of BL. Nevertheless, UAP, particularly at 50–60% amplitudes, affected the emulsion activity and stability of BL. UAP provided BL with high radical scavenging activities and good electron donating ability, especially that from 60% amplitude for 20 min (UAP-60/20). UAP-60/20 showed the impact on change of isoelectric point and molecular characteristic monitored by Fourier transform infrared (FTIR) of BL, compared to those from TP. In addition, BL was also an excellent source of both essential and nonessential amino acids. Therefore, UAP potentially enhanced BL extraction efficiency, resulting the BL with good functional and antioxidative properties.


2021 ◽  
Vol 22 (15) ◽  
pp. 8298
Author(s):  
Hugo Christian Monroy-Ramirez ◽  
Marina Galicia-Moreno ◽  
Ana Sandoval-Rodriguez ◽  
Alejandra Meza-Rios ◽  
Arturo Santos ◽  
...  

Carbohydrates and lipids are two components of the diet that provide the necessary energy to carry out various physiological processes to help maintain homeostasis in the body. However, when the metabolism of both biomolecules is altered, development of various liver diseases takes place; such as metabolic-associated fatty liver diseases (MAFLD), hepatitis B and C virus infections, alcoholic liver disease (ALD), and in more severe cases, hepatocelular carcinoma (HCC). On the other hand, PPARs are a family of ligand-dependent transcription factors with an important role in the regulation of metabolic processes to hepatic level as well as in other organs. After interaction with specific ligands, PPARs are translocated to the nucleus, undergoing structural changes to regulate gene transcription involved in lipid metabolism, adipogenesis, inflammation and metabolic homeostasis. This review aims to provide updated data about PPARs’ critical role in liver metabolic regulation, and their involvement triggering the genesis of several liver diseases. Information is provided about their molecular characteristics, cell signal pathways, and the main pharmacological therapies that modulate their function, currently engaged in the clinic scenario, or in pharmacological development.


Agriculture ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 93
Author(s):  
Pavel Kotyza ◽  
Katarzyna Czech ◽  
Michał Wielechowski ◽  
Luboš Smutka ◽  
Petr Procházka

Securitization of the agricultural commodity market has accelerated since the beginning of the 21st century, particularly in the times of financial market uncertainty and crisis. Sugar belongs to the group of important agricultural commodities. The global financial crisis and the COVID-19 pandemic has caused a substantial increase in the stock market volatility. Moreover, the novel coronavirus hit both the sugar market’s supply and demand side, resulting in sugar stock changes. The paper aims to assess potential structural changes in the relationship between sugar prices and the financial market uncertainty in a crisis time. In more detail, using sequential Bai–Perron tests for structural breaks, we check whether the global financial crisis and the COVID-19 pandemic have induced structural breaks in that relationship. Sugar prices are represented by the S&P GSCI Sugar Index, while the S&P 500 option-implied volatility index (VIX) is used to show stock market uncertainty. To investigate the changes in the relationship between sugar prices and stock market uncertainty, a regression model with a sequential Bai–Perron test for structural breaks is applied for the daily data from 2000–2020. We reveal the existence of two structural breaks in the analysed relationship. The first breakpoint was linked to the global financial crisis outbreak, and the second occurred in December 2011. Surprisingly, the COVID-19 pandemic has not induced the statistically significant structural change. Based on the regression model with Bai–Perron structural changes, we show that from 2000 until the beginning of the global financial crisis, the relationship between the sugar prices and the financial market uncertainty was insignificant. The global financial crisis led to a structural change in the relationship. Since August 2008, we observe a significant and negative relationship between the S&P GSCI Sugar Index and the S&P 500 option-implied volatility index (VIX). Sensitivity analysis conducted for the different financial market uncertainty measures, i.e., the S&P 500 Realized Volatility Index confirms our findings.


2016 ◽  
Vol 66 (1) ◽  
pp. 45-55
Author(s):  
Tadahiro Suzuki ◽  
Yumiko Iwahashi

Symmetry ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 170
Author(s):  
Michal Holčapek ◽  
Nicole Škorupová ◽  
Martin Štěpnička

The article develops further directions stemming from the arithmetic of extensional fuzzy numbers. It presents the existing knowledge of the relationship between the arithmetic and the proposed orderings of extensional fuzzy numbers—so-called S-orderings—and investigates distinct properties of such orderings. The desirable investigation of the S-orderings of extensional fuzzy numbers is directly used in the concept of S-function—a natural extension of the notion of a function that, in its arguments as well as results, uses extensional fuzzy numbers. One of the immediate subsequent applications is fuzzy interpolation. The article provides readers with the basic fuzzy interpolation method, investigation of its properties and an illustrative experimental example on real data. The goal of the paper is, however, much deeper than presenting a single fuzzy interpolation method. It determines direction to a wide variety of fuzzy interpolation as well as other analytical methods stemming from the concept of S-function and from the arithmetic of extensional fuzzy numbers in general.


2021 ◽  
Vol 14 (1) ◽  
pp. 58-67
Author(s):  
Sergey Polyakov ◽  
V. Akimov ◽  
A. Polukazakov ◽  
Vladimir Zolnikov ◽  
P. Enin

The article deals with the issues of modeling and management of life support systems of a residential building. The resulting model of the liquid level in the tank allows you to establish the relationship between the level and the flow rate of the liquid. The results of the selection and justification of the fluid level control structure are presented. An algorithm that implements the operation of a virtual object is given. The structure of the automatic control system (ACS) of the liquid level is technically implemented in an open type. The results confirming the achievability of the proposed structural changes are obtained. The results of experimental studies are presented. The choice and justification of the method of controlling the heating system and the liquid level in the tank are considered. Programs for managing subsystems of a residential building in Assembly language, C++, and ladder diagrams are presented. A model for controlling the liquid level in a Multisim environment is proposed.


1998 ◽  
Vol 44 (12) ◽  
pp. 1115-1136 ◽  
Author(s):  
M J Butler ◽  
A W Day

The relationship of polyketide melanogenesis molecular biology to that of nonmelanin-producing pathways in a wide range of fungi and other organisms is discussed. Analytical methods and fundamental properties of melanins are discussed and fungal melanin properties are compared with those of animal and bacterial melanins. The enzymatic degradation of melanins by lignin peroxidases is described.Key words: fungal melanin, polyketide melanin, DHN melanin, melanin degradation, melanin properties, melanin analysis.


2015 ◽  
Vol 1 (2) ◽  
pp. 67
Author(s):  
Haq Nawaz ◽  
Muhammad Aslam Shad ◽  
Rabia Mehmood ◽  
Tanzila Rehman ◽  
Hira Munir

<p>Functional properties such as protein solubility, swelling capacity, water holding capacity, gelling ability, bulk density and foaming capacity of flours of some commonly used cereals and legume (wheat, refined wheat, maize and chickpea) and their blends were studied. Blends of flours were prepared by mixing equal proportions of selected floors. Statistically significant difference  in studied functional properties except bulk density was observed among cereal flours and their blends. Chickpea flour was found to possess comparatively high water holding capacity, protein solubility index and swelling capacity. The functional properties of maize and wheat flours were found to be improved when blended with chickpea. Chickpea flour and its blends with cereal flours were found to possess good functional score and suggested as favorable candidates for use in the preparation of viscous foods and bakery products. The data provide guidelines regarding the improvement in functional properties of economically favorable cereal flours.<strong></strong></p>


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