https://doi.org/10.17113/ftb.58.04.20.6657

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Antioxidant Capacity of Proteins and Hydrolysates from the Liver of Newborn Piglets, and Their Inhibitory Effects on Steatosis in vitro

Ruilin Zhang, Lasheng Yin, Jian Chen and Xuewu Zhang^*

College of Food Science and Engineering, South China University of Technology, 510640 Guangzhou, PR China

Article history:

Received: 7 February 2020

Accepted: 22 December 2020

Key words:

newborn piglet liver, protein hydrolysates, antioxidant activity, oleic acid, lipid accumulation

Summary:

Research background. Non-alcoholic steatohepatitis is a potentially progressive hepatic disorder that can lead to end-stage liver disease and hepatocellular carcinoma. The inhibitory effects of proteins and hydrolysates from the liver of newborn piglets on hepatic steatosis in oleic-acid-induced HepG2 cells were investigated in vitro.

Experimental approach. The extracted proteins from the liver of newborn piglets (NPLP) were hydrolysed with papain, pepsin, trypsin and Alcalase. Based on comparison of different enzyme digestion condition, a protein hydrolysis protocol was established to obtain hydrolysates with lipid-lowering effect.

Results and conclusions. PLH-trypsin (trypsin-digested NPLP hydrolysate) exhibited strong antioxidant activity and possessed good inhibitory effects on lipogenesis and cholesterol accumulation in HepG2 cells at 150 μg/mL, with a triglyceride decrease of (43±3) % and cholesterol decrease of (31±5) %, comparing with 0.75 mM oleic acid induced model. The addition of NPLH-trypsin (300 μg/mL) decreased alanine aminotransferase and aspartate aminotransferase activities and increased superoxide dismutase activity.

Novelty and scientific contribution. This study demonstrated that NPLH-trypsin have a potential preventive effect on NAFLD in its early stage, and NPLH-trypsin has potential use as the modulator of lipid overaccumulation disease in food supplements.

https://doi.org/10.17113/ftb.58.04.20.6717

Phenylalanine Alleviates Postharvest Chilling Injury of Plum Fruit by Modulating Antioxidant System and Enhancing the Accumulation of Phenolic Compound

Ommol Banin Sogvar¹, Vali Rabiei^1*, Farhang Razavi¹ and Gholamreza Gohari²

¹Department of Horticulture, Faculty of Agriculture, University of Zanjan, University Blvd., 45371-38791, Zanjan, Iran

²Department of Horticulture, Faculty of Agriculture, University of Maragheh, Daneshgah Blvd., Madar Square, 83111-55181, Maragheh, East Azarbaijan, Iran

Article history:

Received: 25 March 2020

Accepted: 2 December 2020

Key words:

antioxidant capacity, chilling injury, phenylalanine, plum fruit, phenylalanine ammonia-lyase (PAL)

Summary:

Research background. Low temperature storage causes chilling injury in plum (Prunus domestica L.) fruits. Consequently, any treatments with beneficial effects on these symptoms would achieve attention. For this purpose, phenylalanine treatments were applied on ‘Stanley’ plum fruits. The main purpose of the present study was to investigate the influence of the exogenous application of phenylalanine on fruit quality, chilling tolerance, and antioxidant capacity of ‘Stanley’ plums during cold storage.

Experimental approach. Phenylalanine at different concentrations were applied on ‘Stanley’ plums. Following phenylalanine application, plums were cold stored. Chilling injury, antioxidant capacity, electrolyte leakage, malondialdehyde, proline, and internal contents of anthocyanin, flavonoids, phenols, ascorbic acid, and some antioxidant enzymes were assessed.

Results and conclusions. Phenylalanine treatment significantly alleviated chilling injury in plum fruits by enhancing antioxidant capacity and increasing the activity of phenylalanine ammonia lyase enzyme (PAL). Phenylalanine-treated fruits had higher levels of ascorbic acid, anthocyanin, flavonoids, and phenols, as well as a higher total antioxidant activity, than the control fruits during low temperature storage. Phenylalanine at 7.5 mM was the most effective treatment in enhancing the activity of PAL and the accumulation of phenolic compounds and in reducing the severity of chilling injury. Treatments delayed mass loss and maintained fruit firmness. In addition, the application of 7.5 mM phenylalanine improved the activities of antioxidant enzymes (superoxide dismutase, catalase, and ascorbate peroxidase), decreased the accumulation of hydrogen peroxide, and increased the endogenous content of proline. Moreover, phenylalanine maintained membrane integrity, manifested by a reduced electrolyte leakage and malondialdehyde accumulation.

Novelty and scientific contribution. In the current study, chilling injury had a positive correlation with the activities of PAL and antioxidant enzymes. However, negative correlations were observed between chilling injury and ascorbic acid content and antioxidant capacity. Considering the results, phenylalanine treatment could be spotted as an encouraging approach to alleviate the severity of chilling injury and thus preserve nutritional quality of plums during low temperature storage.

https://doi.org/10.17113/ftb.58.04.20.6734

Characterization of Collagen from Sakhalin Taimen Skin as Useful Biomass

Takeshi Nagai^1,2,3*, Masataka Saito⁴, Yasuhiro Tanoue⁵, Norihisa Kai⁶ and Nobutaka Suzuki⁷

¹Graduate School of Agricultural Sciences, Yamagata University, 9978555 Yamagata, Japan

²The United Graduate School of Agricultural Sciences, Iwate University, 0208550 Iwate, Japan

³Graduate School, Prince of Songkla University, 90112 Songkhla, Thailand

⁴Kagawa Nutrition University, 3500288 Saitama, Japan

⁵Department of Food Science and Technology, National Fisheries University, 7596595 Yamaguchi, Japan

⁶Department of Integrated Science and Technology, Oita University, 8701192 Oita, Japan

⁷Nagoya Research Institute, 4701131 Aichi, Japan

Article history:

Received: 7 April 2020

Accepted: 17 December 2020

Key words:

Sakhalin taimen skin, useful biomass, collagen, succinylation, improvement of functional property

Summary:

Research background. Animal collagen has been widely utilized in foods, cosmetics and biomedical fields. The non-edible parts, such as fish skin and bones, are generated during cooking processes. Most of them are currently discarded as waste, although the nutritional values of the skins and bones are high. It needs to utilize the non-edible parts for the reduction of environmental impact, as it may be one of source of environmental pollution.

Experimental approach. Collagen was prepared from Sakhalin taimen skins as wastes generated during cooking processes. Next, the colour, SDS-polyacrylamide gel electrophoresis, ultraviolet absorption, subunit composition, amino acid composition, denaturation temperature, and attenuated total reflectance-Fourier transform infrared spectroscopy analysis were conducted to explore the properties of the collagen. Lastly, it tried to improve the functional properties of the collagen using chemical modification technique for future applications.

Results and conclusions. Cold acetone treatment made it possible to easily remove the fats and pigments from skins. The odorless and pure-white collagen was obtained with high-yield. The α3 chain did not exist in the collagen. Sakhalin taimen skin collagen had rich α-helix and low β-sheet structures. Succinylation caused the secondary structural changes of the collagen molecule. Moreover, succinylation made it possible not only to increase the viscosity of collagen solution and but also to improve the solubility of collagen in the physiological conditions around pH=6.

Novelty and scientific contribution. This finding was the first report on the absence of the α3 chain in Salmonid fish skin collagens. The succinylated collagen from Sakhalin taimen skin as useful biomass has potential to utilize in foods, cosmetics, and its related industries.

https://doi.org/10.17113/ftb.58.04.20.6622

Enhanced Microencapsulation of C-Phycocyanin from Arthrospira by Freeze-Drying with Different Wall Materials

Wanida Pan-utai^1* and Siriluck Iamtham^2,3,4,5,6

¹Institute of Food Research and Product Development, Kasetsart University, Chatuchak, Bangkok 10900, Thailand

²Department of Science, Faculty of Liberal Arts and Science, Kasetsart University, Kamphaeng Saen Campus, Nakhon Pathom 73140, Thailand

³Center for Agricultural Biotechnology, Kasetsart University, Kamphaeng Saen Campus, Nakhon Pathom 73140, Thailand

⁴Center of Excellence on Agricultural Biotechnology: (AG-BIO/PERDO-CHE), Bangkok 10900, Thailand

⁵Center for Advanced Studies in Tropical Natural Resource, NRU-KU, Kasetsart University, Chatuchak, Bangkok 10900, Thailand

⁶Research Unit of Orchid Tissue Culture, Kasetsart University, Kamphaeng Saen Campus, Nakhon Pathom 73140, Thailand

Article history:

Received: 2 January 2020

Accepted: 2 December 2020

Key words:

phycocyanin, Arthrospira, microencapsulation, freeze-drying, antioxidant properties

Summary:

Research background. C-phycocyanin (C-PC) as a water-soluble blue pigment was extracted from microalga Arthrospira. C-PC could be a good substitute for synthetic pigments with high antioxidant activity. However, C-PC is unstable due to sensitivity to temperature, light, pH, and oxygen; therefore applications of C-PC in food and other products are limited. Microencapsulation of C-PC using freeze-drying is a solution to this problem and is considered a suitable method for drying heat-sensitive pigment.

Experimental approach. C-phycocyanin was extracted from Arthrospira platensis. C-phycocyanin microcapsules were modified by freeze-drying, with different ratios at 0-100 % of maltodextrin (MD) and gum Arabic (GA) used as microencapsulation wall materials. The powders produced were evaluated for physical properties including moisture content and water activity, solubility, hygroscopicity, bulk density, colour appearance, particle morphology and size distribution. Thermal stability and antioxidant activity of freeze-dried C-PC microencapsulated powders were also assessed.

Results and conclusions. Freeze-dried C-PC microencapsulated powders with maltodextrin and gum Arabic as wall materials gave high encapsulation efficiency of around 99 %. At higher gum Arabic percentage, moisture content decreased and water activity improved. Maltodextrin gave higher solubility of C-PC powders whereas gum Arabic led to a similar colour of C-PC without microencapsulation. Freeze-dried C-PC microencapsulated powders were composed of different sized microparticles regardless of the combination of wall materials with amorphous glassy shapes. Thermal stability of encapsulated C-PC increased and also showed high antioxidant properties. 

Novelty and scientific contribution. C-PC microcapsules that maintain colourant stability with high antioxidant levels and resistance to high temperatures can be applied in a wide variety of products and also in the food industry.