Search results for "browning"

Detection of Invisible Damages in ‘Rojo Brillante’ Persimmon Fruit at Different Stages Using Hyperspectral Imaging and Chemometrics

2021

[EN] The main cause of flesh browning in 'Rojo Brillante' persimmon fruit is mechanical damage caused during harvesting and packing. Innovation and research on nondestructive techniques to detect this phenomenon in the packing lines are necessary because this type of alteration is often only seen when the final consumer peels the fruit. In this work, we have studied the application of hyperspectral imaging in the range of 450-1040 nm to detect mechanical damage without any external symptoms. The fruit was damaged in a controlled manner. Later, images were acquired before and at 0, 1, 2 and 3 days after damage induction. First, the spectral data captured from the images were analysed through…

Study and characterization of polyphenol oxidase from eggplant (Solanum melongena L.)

2011

ABSTRACT: In this study the catecholase and cresolase activities of eggplant polyphenol oxidase (PPO) were investigated. Enzyme activity was determined by measuring the increase in absorbance using catechol as substrate and 3-methyl-2- benzothiazolinone hydrazone (MBTH) as coupled reagent. The effects of substrate specificity, heat inactivation, temperature, pH, and inhibitors were investigated to understand the enzymatic alteration of ready-to-eat preparations. Browning of vegetables was determined through a colorimeter. Decrease of lightness (L*) and increase of color difference values (ΔE*) were correlated with tissue browning. Antibrowning agents were tested on PPO under the same condit…

Baltic Journal of English Language, Literature and Culture, N 6

2016

Agronomic performance and fruit quality in greenhouse grown eggplant are interactively modulated by iodine dosage and grafting

2022

Iodine (I) is considered an indispensable trace element for humans due to its capacity to promise a normal functions of thyroid hormones, preventing cretinism, goiter, reproductive failure, and diverse types of brain injury. Vegetable grafting is a technique for securing yield constancy and/or improving fruit quality. The study evaluated the combined effect of I-dosages and grafting onto Solanum torvum rootstock on 'Birgah' eggplant. Iodine at 100 or 300 mg L-1 enhanced marketable yield by 28.8% and 8.5%, respectively, compared with the control. Plants grafted onto S. torvum and self-grafted plants increased marketable yield by 53.0% and 45.8%, respectively compared with the ungrafted plant…

Effect of a novel physical pretreatment process on the drying kinetics of seedless grapes

2000

In this paper an alternative physical method for enhancing the drying rate of seedless grapes is proposed. It consists of the superficial abrasion of the grape peel using an inert abrasive material. The effectiveness of this novel process was compared to that of the traditional ethyl oleate dipping process by analysing not only their respective drying times, but also the peel surfaces by scanning electron microscopy. Moreover, the drying kinetics of the above two treatments was reconstructed by using a mathematical model in which the grape pretreatment used was assumed to affect the water diffusivity in the grape peel, but not in the grape pulp. Even though the abrasion method was found to …

Allochthony, fatty acid and mercury trends in muscle of Eurasian perch (Perca fluviatilis) along boreal environmental gradients

2022

Environmental change, including joint effects of increasing dissolved organic carbon (DOC) and total phosphorus (TP) in boreal northern lakes could potentially affects food web energy sources and the biochemical composition of organisms. These environmental stressors are enhanced by anthropogenic land-use and can decrease the quality of polyunsaturated fatty acids (PUFAs) in seston and zooplankton, and therefore, possibly cascading up to fish. In contrast, the content of mercury in fish increases with lake browning potentially amplified by intensive forestry practises. However, there is little evidence on how these environmental stressors simultaneously impact beneficial omega-3 fatty acid …

Effect of refrigerated storage on microbiological, chemical and sensory characteristics of a ewes’ raw milk stretched cheese

2017

This study aimed to describe the effects of refrigerated storage up to 180 days on microbiological, chemical, physical, and sensory characteristics of a PDO ewes’ raw milk stretched cheese. To this aim, a total of 224 cheeses were manufactured in four consecutive production weeks, and series of 32 of them were examined before packaging and after 15, 30, 60, 90, 120, and 180 d of storage at 4 ± 2 °C in the dark, respectively. Lactic acid bacteria cocci displayed the highest levels (7.8 Log CFU*g−1) during early storage and decreased progressively over time (7.4 Log CFU*g−1), while the opposite trend was observed for lactic acid bacteria rods (from 6.5 to 7.3 Log CFU*g−1). TMC and enterocci s…

Effect of cold storage on the quality of minimally processed cauliflower

2015

Cauliflower has been described as a vegetable with a high nutritional value due to its important content of vitamins, antioxidants and anti-carcinogenic compounds. Cauliflower inflorescences are harvested while they are totally immature, which implies severe changes in nutrient, water and hormonal status. Harvesting and the following processing can cause a severe stress determining the appearance of accelerated senescence symptoms. The effects of processing and cold storage of minimally processed green cauliflower were investigated. Florets were treated with antioxidants before storage in PE bags at 4°C for 21 days. During storage, weight loss, colour, firmness, soluble solids content and p…

Color of orange juice treated by High Intensity Pulsed Electric Fields during refrigerated storage and comparison with pasteurized juice

2008

Abstract High Intensity Pulsed Electric Field (HIPEF) is one of the nonthermal minimal processing technologies interesting for scientists and food industry as a new, alternative (preservation) process for liquid food. We have evaluated the effect on color, browning and hydroxymethylfurfural (HMF) of a pasteurized orange juice and the same orange juice treated by HIPEF, during 7 weeks stored in refrigeration at 2 °C and 10 °C. Pasteurized orange juice presents greater yellow tendency ( b ∗ ) and less red tendency ( a ∗ ) than the untreated orange juice, while HIPEF orange juice presents a coloration more similar to the untreated orange juice. Color variations (Δ E ) during storage are greate…

Full inhibition of enzymatic browning in the presence of thiol-functionalised silica nanomaterial

2018

[EN] Darkening processed fruits and vegetables is caused mainly by enzymatic browning through polyphenol oxidase (PPO) action. Accordingly, we explored the potential of four silica-based materials (MCM-41 nanometric size, MCM-41 micrometric size, UVM-7 and aerosil), non-functionalised and functionalised with thiol groups, to inhibit PPO activity in the model system and apple juice. All materials showed relevant performance when immobilising and inhibiting PPO in model systems, and support topology is a main factor for enzyme immobilisation and inhibition. Thiol-containing silica UVM7-SH showed the greatest inactivation, and similar browning values to those obtained by acidification. The enz…