Anthocyanins are the most abundant flavonoid constituents of fruits and vegetables. The conjugated bonds in their structures, which absorb light at about 500 nm, are the basis for the red, blue and ...purple colours of fruits, vegetables and their products. Anthocyanin pigments readily degrade during thermal processing which can have a dramatic impact on colour quality and may also affect nutritional properties. This review attempts to summarize some important aspects of anthocyanin degradation during thermal processing. Conclusions regarding the mechanisms and kinetics of anthocyanin degradation during heat treatment are postulated based on current findings.
•Recent advances in ultrasound combined processes are detailed.•Hybrid combination of ultrasound with conventional techniques.•Innovative combinations of ultrasound with modern techniques.•Ultrasound ...combination techniques as efficient tool for food processing.
Ultrasound has a significant effect on the rate of various processes in food, perfume, cosmetic, pharmaceutical, bio-fuel, materials, or fine chemical industries, despite some shortcomings. Combination with other conventional or innovative techniques can overcome these limitations, enhance energy, momentum and mass transfer, and has been successfully demonstrated in many recent studies. Various ultrasound combined hybrid and innovative techniques are systematically summarized in this review for the first time. Ultrasound can be combined with diverse conventional techniques including Soxhlet, Clevenger, enzyme, hydrotropes, ionic liquids, Deep Eutectic Solvents (DES) or Natural Deep Eutectic Solvents (NADES), to enhance mixing and micro-mixing, reduced thermal and concentration gradients, and selective extraction. Moreover, combinations of ultrasound with other innovative techniques such as microwave, extrusion, supercritical fluid, subcritical and pressure liquids, Instant controlled pressure drop (DIC), Pulsed Electric Field (PEF), Ultra-Violet (UV) or Infra-Red (IR) radiations, Counter-current chromatography (CCC), or centrifugal partition chromatographs (CPC) can enable reduced equipment size, faster response to process control, faster start-up, increased production, and elimination of process steps. The theories and applications of these ultrasound combined hybrid and innovative techniques as well as their advantages and limitations are compared, and further perspectives are proposed. This review provides new insights into advances in ultrasound combined techniques and their application at research, educational, and industrial level in modern food and plant-based chemistry.
Novel disinfectants for fresh produce Joshi, Kompal; Mahendran, R.; Alagusundaram, K. ...
Trends in food science & technology,
11/2013, Letnik:
34, Številka:
1
Journal Article
Recenzirano
Fresh produce such as fruit and vegetables are known carriers of pathogenic microorganisms that often lead to outbreaks of food borne illnesses and public health scares. During the processing of ...fresh produce strong sanitizers and disinfectants are often required to remove the microbiological load left behind by washing. While such sanitizers and disinfectants must be highly efficacious as an anti-microbial agent, at the same time they must be cost effective, environmentally friendly, non-hazardous to public health and have insignificant effect on the nutritional and organoleptic properties of the fresh produce. This paper reviews the efficacy of various disinfectants to reduce the microbial spoilage and to increase the shelf life of fresh produce without compromising the quality of the end product. Inactivation of microbes using various disinfectants and parameters governing for inactivation are detailed. This review identifies the safest disinfectants that inactive pathogens while maintaining the sensory quality of fresh produce.
•Efficacy and application of novel chemical disinfectants are reviewed.•Antimicrobial properties of novel chemical disinfectants.•Advantages and disadvantages of novel chemical disinfectants over classical disinfectants.•Application of novel chemical disinfectants.
In the last decade power ultrasound has emerged as an alternative processing option to conventional thermal approaches for pasteurisation and sterilisation of food products. While sonication alone ...may not be adequate for inactivation of various spoilage and harmful enzymes present in food, ultrasound in combination with mild heat treatment and/or pressure has shown potential for both enzyme and pathogen inactivation. Numerous studies have investigated ultrasound for inactivating enzymes such as pectinmethylesterase, polyphenoloxidases and peroxidases responsible for deterioration of fruit & vegetable juice and various enzymes pertinent to milk quality. The efficacy of ultrasound for the inactivation of enzymes in food is outlined in this review along with a description of the inactivation mechanism to elucidate the effect of ultrasound on important enzymes in fruit juices and dairy products.
•Novel technologies for improved extraction yields of hydrocolloids.•Clean and green innovative approaches for hydrocolloids are reviewed.•Synergistic combinations of novel and/or conventional ...technologies are reviewed.•Challenges associated with industrial scale up of technologies.
The macroalgal hydrocolloid industry is a rapidly growing industry with an annual growth in the global production of 2–3 %. Hydrocolloids from macroalgae are mainly in the form of polysaccharides with other nutrients, such as vitamins, minerals, and proteins. Due to its potential industrial applications, macroalgae have been used as raw materials for hydrocolloids extraction. Compared to the conventional extraction methods, emerging innovative assisted extraction technologies (e.g., Ultrasound/Microwave assisted extraction) have been developed to maximise the extraction yields, efficiency and thereby, maintaining sustainability along the process. These novel techniques are considered as clean and green strategies, with a potential for a large-scale production; thus, avoiding or reducing the use of chemicals. However, more research is required to establish their mechanism of action in order to finally implement them at industrial level. This paper reviews the most relevant strategies and technologies involved in the production of hydrocolloids from macroalgae.
Economic dispatch is a highly constrained optimization problem encompassing interaction among decision variables. Environmental concerns that arise due to the operation of fossil fuel fired electric ...generators, transforms the classical problem into multiobjective environmental/economic dispatch (EED). In this paper, a fuzzy clustering-based particle swarm (FCPSO) algorithm has been proposed to solve the highly constrained EED problem involving conflicting objectives. FCPSO uses an external repository to preserve nondominated particles found along the search process. The proposed fuzzy clustering technique, manages the size of the repository within limits without destroying the characteristics of the Pareto front. Niching mechanism has been incorporated to direct the particles towards lesser explored regions of the Pareto front. To avoid entrapment into local optima and enhance the exploratory capability of the particles, a self-adaptive mutation operator has been proposed. In addition, the algorithm incorporates a fuzzy-based feedback mechanism and iteratively uses the information to determine the compromise solution. The algorithm's performance has been examined over the standard IEEE 30 bus six-generator test system, whereby it generated a uniformly distributed Pareto front whose optimality has been authenticated by benchmarking against the epsiv -constraint method. Results also revealed that the proposed approach obtained high-quality solutions and was able to provide a satisfactory compromise solution in almost all the trials, thereby validating the efficacy and applicability of the proposed approach over the real-world multiobjective optimization problems.
• Potential benefit of capsaicinoids for weight management. • Beneficial effects on lipid oxidation and energy expenditure. • Demonstrates inter-relationship between capsaicinoid compounds and ...appetite.
Capsaicinoids are a group of chemicals found in chilli peppers, with bioactive properties. The purpose of this study is to systematically review research investigating the potential benefits capsaicinoid compounds may have in relation to weight management. Medical databases were searched and 90 trials found, 20 of which were selected for inclusion, involving 563 participants. Three main areas of potential benefit for weight management were found: (1) increased energy expenditure; (2) increased lipid oxidation and (3) reduced appetite. Trial duration, dosage and sized varied, though trials were generally of high quality with a low risk of bias. It was observed that consumption of capsaicinoids increases energy expenditure by approximately 50kcal/day, and that this would produce clinically significant levels of weight loss in 1–2years. It was also observed that regular consumption significantly reduced abdominal adipose tissue levels and reduced appetite and energy intake. The mechanism of action is not presently fully understood, although it is well accepted much of the effects are caused by stimulation of the TRPV1 receptor. While capsaicinoids are not a magic bullet for weight loss, the evidence is that they could play a beneficial role, as part of a weight management program.
Power ultrasound is recognised as a potential non-thermal technique to inactivate micro-organisms pertinent to fruit juices. In this study tomato juice was sonicated at different amplitude levels ...(24.4–61.0
μm) at a constant frequency of 20
kHz for treatment times (2–10
min) and pulse durations of 5
s on and 5
s off. Hunter colour values (
L∗,
a∗ and
b∗), pH, °Brix, titratable acidity, ascorbic acid and yeast inactivation were measured. No significant differences (
p
<
0.05) in pH, °Brix or titratable acidity were observed. Regression modelling was used to investigate the main effects of amplitude level and treatment time. Prediction models were found to be significant (
p
<
0.05) with low standard errors and high coefficients of determination (
R
2). Model predictions for critical quality parameters of Hunter colour values (
L∗,
a∗ and
b∗), ascorbic acid and yeast inactivation were closely correlated with the experimental results obtained.
The effects of sonication on pH, °Brix, titratable acidity (TA), cloud, browning index, and color parameters (L*, a*, and b*) of freshly squeezed orange juice samples were studied. Ultrasonic ...intensity (UI) levels of 8.61, 9.24, 10.16, 17.17, and 22.79 W/cm2 and treatment times of 0 (control), 2, 4, 6, 8, and 10 min were investigated. No significant changes in pH, °Brix, and TA (p < 0.05) were found. Cloud value, browning index, and color parameters were significantly affected by ultrasonic intensity and treatment time. Changes in cloud value followed first-order kinetics, whereas browning index, L*, a*, and b* values followed zero-order kinetics. Reaction rate constants were linearly correlated (R 2 > 0.90) to ultrasonic intensity.
Aims
The study aimed to investigate the inactivation efficacy and mechanisms of plasma activated water (PAW) on selected bacteria in planktonic state.
Methods and Results
Plasma activated water was ...generated using an atmospheric cold plasma jet at 15, 22 and 30 kV for 5 min. Escherichia coli, Listeria innocua, Staphylococcus aureus, Aeromonas hydrophila, Pseudomonas fluorescens and Shewanella putrefaciens were selected as the representative bacterial species. Each bacterial suspension was inoculated into PAW immediately after generation, and the viable counts at different exposure times of 0·5, 1, 3, 5 and 24 h during 4°C storage were measured to determine the inactivation efficacy. Scanning electron microscopy images of the bacteria were conducted to examine the structural changes. Physicochemical properties of PAW, including pH, conductivity, oxidation reduction potential (ORP), and reactive species of H2O2, NO2− and NO3− were measured. The results demonstrated that inactivation efficacy was in positive correlation with voltage and exposure time. Gram‐negative bacteria were more susceptible to PAW than Gram‐positive bacteria. Morphology damage was observed for all the bacterial species. PAW was significantly acidified, conductivity and ORP were significantly increased, and reactive species were detectable after 48 h.
Conclusions
This study offered a better understanding of the inactivation mechanisms of PAW, and the inactivation efficacy can be affected by voltage, exposure time and bacterial species.
Significance and Impact of the Study
This study demonstrated the potential usage of PAW as an alternative disinfectant.
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