Surface color changes of oak (Quercus alba L.) treated with dopamine and iron ion compounds by acceleration of temperature–humidity condition

Author(s):  
Ru Liu ◽  
Hongyun Qiu ◽  
Jianfeng Xu ◽  
Xiaoyan Li ◽  
Ling Long
Foods ◽  
2018 ◽  
Vol 8 (1) ◽  
pp. 7 ◽  
Author(s):  
Edgar Cambaza ◽  
Shigenobu Koseki ◽  
Shuso Kawamura

Deoxynivalenol (DON) is a well-known mycotoxin, responsible for outbreaks of gastrointestinal disorders in Japan. Fusarium graminearum, a parasite of cereal crops, produces this toxin and this is one of the reasons why it is important to understand its metabolism. It is possible to predict the mold’s color change and the quantity of DON synthesized throughout its lifecycle. Furthermore, aw has been found to affect the amount of DON. This study aimed to analyze the potential of F. graminearum surface color as a predictor of DON concentration at aw = 0.94, 0.97, and 0.99. Thus, 36 specimens were incubated at 25 °C, 12 at each aw. After 4, 8, 12, and 16 days, three specimens from each aw were collected for color analysis and DON quantification. For color analysis, photos were taken and red, green and blue (RGB) channels were measured on ImageJ software. DON was quantified through liquid chromatography (HPLC). Color changes were only observed at aw = 0.99 because at lower aw the molds presented high growth of white mycelium. Yet, DON increased in all cases. It was only possible to relate the colors with DON concentration at aw = 0.99, where they presented inverse proportionality.


2007 ◽  
Vol 4 (4) ◽  
pp. 100295
Author(s):  
S. W. Dean ◽  
Deng-Fong Lin ◽  
Huan-Lin Luo ◽  
Jen-Rong Lee
Keyword(s):  

1991 ◽  
Vol 116 (3) ◽  
pp. 482-490 ◽  
Author(s):  
Georges T. Dodds ◽  
J. Wyatt Brown ◽  
Pamela M. Ludford

Chilling of mature-green (MG) tomato fruit (Lycopersicon esculentum Mill. and related species) was investigated to determine the effect of chilling stress on surface color during low-temperature storage. Color measurements were made with a tristimulus calorimeter (L, a, b values), and data were analyzed by multivariate analysis of variance and canonical variates analysis. Changes in surface color of MG fruit during chilling were not correlated overall with relative chilling sensitivity of cultivars/lines; however, within standard and cherry types, chilling-tolerant fruit changed surface color more during chilling than chilling-sensitive fruit when fruit were picked early in the season. Early harvests were less chilling-sensitive than late harvests. The number of hours below 15.6C in the 200 hours before harvest was positively correlated with postharvest chilling sensitivity. A high vs. ambient relative humidity during storage did not affect chilling-induced percent change in color. Tobacco mosaic virus resistance led to less and Verticillium albo-strum Reinke & Berthier resistance led to more chilling-induced color change. There was no effect from resistances to Fusarium oxysporum Schlechtend f. sp. lycopersici (Sacc.) W.C. Snyder & H.N. Hans, alternaria stem canker (Alternaria solani Sorauer), anthracnose [Colletotrichun coccodes (Wallr.) S.J. Hughes], root-knot nematode (Meloidogyne hapla Chitwood), Phytophthora infestans (Mont.) deBary, or Stemphylium botryosum f. sp. lycopersici Rotem, Cohen, & Wahl. Our results show harvest date had an effect on chilling-induced changes in surface-color in MG fruit.


2008 ◽  
pp. 63-68 ◽  
Author(s):  
Dobrila Randjelovic ◽  
Ljubo Vracar ◽  
Aleksandra Tepic

Fast frozen blackberry partially change its surface color from characteristic black to copper-redish color. This change decreases the market value, especially when the product is intended for export. For these reasons classic tunnels for slow freezing are being more widely used nowadays. In order to clarify mentioned phenomena, a detailed monitoring of preparation process and freezing, as well as changes of frozen blackberry fruits in industrial conditions was carried out. Along with sensory evaluation of surface color changes, chemical analysis of reference parameters of fresh and frozen fruits were performed. The results of sensory evaluation confirmed evident color change of fruits frozen by slow (and fast) treatment; the chemical analysis confirmed unchanged total solids and anthocyanin content, as well as changes in pH value and vitamin C, in comparison to fresh blackberry fruits.


2018 ◽  
Vol 37 (12) ◽  
pp. 1490-1497 ◽  
Author(s):  
Ivan Klement ◽  
Tatiana Vilkovská ◽  
Jacek Baranski ◽  
Aleksandra Konopka

1995 ◽  
Vol 120 (4) ◽  
pp. 650-655 ◽  
Author(s):  
Artur Miszczak ◽  
Charles F. Forney ◽  
Robert K. Prange

`Kent' strawberries were harvested at red, pink, and white stages of development, and stored at 15C in the light. Fruit were sampled over a 10-day period and evaluated for volatile production and surface color. Volatile production by red and pink fruit peaked after 4 days of storage. Maximum volatile production by red fruit was 8- and 25-fold greater than maximum production by pink and white fruit, respectively. Aroma volatiles were not detected in the headspace over white berries until 4 days following harvest after which volatile production increased through the tenth day of storage. Changes in the surface color of white berries during postharvest ripening coincided with the production of volatiles. In another experiment, red, pink, and white `Kent' strawberries were stored for 3 days at 10 or 20C in the dark or light. Fruit were then evaluated for volatile production, weight loss, anthocyanin content, and surface color changes. White berries produced volatile esters after 3 days of storage at 20C in the light. Both light and temperature influenced the relative production of the volatiles produced by pink fruit. Fresh weight loss, color change, and anthocyanin content were temperature and light dependent.


BioResources ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. 4934-4946
Author(s):  
Zhizhong Long ◽  
Liqiang Zhang ◽  
Zhili Tan ◽  
Qingding Wu ◽  
Jin Yan

Binderless poplar powder compacts were prepared using the hot-pressing technology. The effect of the forming process on the mechanical properties and surface color of the poplar powder compacts was studied. The effect of forming temperature on mechanical properties and surface color was more noticeable than the forming pressure and the holding time. With the change of the forming process parameters, the static bending strength of the compacts increased first and then decreased. The overall change trend of the surface hardness increased continuously. The overall color difference (ΔE*) of the compacts increased with the change of forming process parameters and the surface color deepened gradually. The results of Fourier transform infrared (FTIR) spectroscopy showed that hemicellulose, cellulose, and lignin in the compacts were greatly affected by the forming process parameters. The degradation of hemicellulose and cellulose produced many colored substances, and the content of lignin increased. These made the surface color of compacts deepen.


2019 ◽  
Vol 16 (2) ◽  
pp. 49
Author(s):  
Budiono Budiono ◽  
Nabila Farah Khoirunnisa ◽  
Seffy Vera Faylina

The advantages of Nanohybrid composite resin are they have a smooth surface and greater strength, also minimal shrinkage. The disadvantages of composite resin are the color changes extrinsically and intrinsically. The color is changing extrinsically because of the dyes which attached to the surface of the composite resin and the color is changing intrinsically due to oxidation of monomers. Pempek and turmeric-tamarind herbal drink (jamu) are kind of foods and beverages that are very popular among Indonesian people, both of them are causing discoloration on the surface of the composite resin. The objective was to identify the difference composite resin color change after soaking in sweet and sour sauce (cuko pempek) and turmeric-tamarind herbal drink. This study was experimental laboratory research with pre-test and post-test research design. The samples were 32 pieces of Nanohybrid composite resin with the size of 10 x 2 mm. 16 samples of each test were soaked in 5 ml “cuko pempek” and turmeric-tamarind herbal drink in 37 0 C temperature in 7 days. The color change was measured using spechtrophotometer (UV-2401 PC). Results: There are differences between Nanohybrid composite resin surface color change which were soaked in “cuko pempek” and turmeric-tamarind herbal drink which marked in an average change of dE*ab “cuko pempek” (4.7244) and turmeric and tamarind herbal drink (39.1944). The results of independent T-Test also showed a significant color change that is p = 0,000 (p <0.05). This study concluded that there were differences between Nanohybrid composite resin surface color change which are soaked in “cuko pempek” and turmeric-tamarind herbal drink.


2007 ◽  
pp. 53-58 ◽  
Author(s):  
Ljubo Vracar ◽  
Aleksandra Tepic ◽  
Biserka Vujicic ◽  
Srdjan Solaja

Red pepper (Capsicum annuum L.) is one of the most important vegetables in the world. The main ground pepper quality attributes are extractable color, surface color, qualitative and quantitative carotenoid content. In this work, the influence of heat treatment on ground pepper quality was investigated. Microbiological status was examined in non-sterilized and sterilized ground pepper. Color changes were assessed by measuring the extractable color (ASTA) and surface color, using a photocolorimeter. The obtained results showed that at the end of experiment, non-sterilized samples had higher color values in comparison to the sterilized ones. Also, color deterioration was heightened at room temperature.


Sign in / Sign up

Export Citation Format

Share Document