•Relevance of ultrasound in food processing.•Ultrasound-assisted extraction and freezing process.•Mechanisms on the basis of sono-physical and chemical effects of ultrasound.•Food components ...modifications under sonication treatments.•Trends, challenges and recommendations on ultrasound in food processing.
Ultrasound is an advanced non-thermal food-processing technology that has received increasing amounts of interest as an alternative to, or an adjuvant method for, conventional processing techniques. This review explores the sono-physical and sono-chemical effects of ultrasound on food processing as it reviews two typical food-processing applications that are predominantly driven by sono-physical effects, namely ultrasound-assisted extraction (UAE) and ultrasound-assisted freezing (UAF), and the components modifications to food matrices that can be triggered by sono-chemical effects. Efficiency enhancements and quality improvements in products (and extracts) using ultrasound are discussed in terms of mechanism and principles for a range of food-matrix categories, while efforts to improve existing ultrasound-assist patterns was also seen. Furthermore, the progress of experimental ultrasonic equipments for UAE and UAF as food-processing technologies, the core of the development in food-processing techniques is considered. Moreover, sono-chemical reactions that are usually overlooked, such as degradation, oxidation and other particular chemical modifications that occur in common food components under specific conditions, and the influence on bioactivity, which was also affected by food processing to varying degrees, are also summarised. Further trends as well as some challenges for, and limitations of, ultrasound technology for food processing, with UAE and UAF used as examples herein, are also taken into consideration and possible future recommendations were made.
Despite a substantial body of research to date for the detection of microplastics (MPs) in almost every environmental compartment there remains a lack of standardisation, and methodologies used by ...different research groups vary widely. Chemical imaging, which provides simultaneous measurement of physical (i.e. spatial) and chemical (i.e. spectroscopic) information, is recognized as a promising tool for MPs analysis. Herein, we first review the state-of-the-art chemical imaging methods, i.e., Fourier-transform infrared spectroscopy (FTIR) and Raman imaging, for the identification and quantification of MPs from different environmental samples. From a technical point of view (e.g., accuracy, speed optimizations and background effects), the limitations and analytical challenges are highlighted from extensive literature data. Finally, we suggest possible strategies and solutions to improve current practices towards an automated routine for MPs analysis.
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•State-of-the-art chemical imaging methods for microplastics analysis are reviewed.•The limitations and analytical challenges for chemical imaging are highlighted.•We suggest strategies to improve current practices towards an automated routine.•We advocate for more research devoted to methodology development.
Increased demand of edible oil throughout the world has resulted in establishment of many edible oil industries leading to generation of huge amount of wastewater. Wastewater is generated mostly ...during the processing operations and washing of equipments. This wastewater has high nutrient content, biological oxygen demand (BOD), chemical oxygen demand (COD), lipids (fats, oil and grease) and organic and inorganic contents, so if disposed untreated it can result in soil, water and air pollution.
This review is aimed to describe different methods used by edible oil industries to treat wastewater and their efficiency for removal of pollution. Especially, focuses on different utilizations of wastewater as a resource from edible oil industry.
Physiochemical (i.e. coagulation/flocculation), biological (i.e aerobic and anaerobic) and electrochemical methods are used for treatment of edible oil industry wastewater. These methods can be used alone or in combination for effective treatment Alternatively, utilization of wastewater is the most recent approach which is not only reduce pollution but also lead to the recovery of useful industrial products, such as bioactive compounds, bioplastic, biofuel, biofertilizer, biopesticide, enzymes, single cell proteins and many more. Moreover, bioactive compounds (i.e. polyphenols) can be extracted and used in different food products which leads to generate potential future possibilities for food and agriculture industries.
•Edible oil industries generates a considerable amount of wastewater.•Physiochemical methods can be used as initial process.•Wastewater from edible oil industries can be utilized for valuable products.•Extracted compounds from wastewater can be used in food products.
•UAE of cyanidin-3-galactoside was successfully optimized.•Lower ultrasonic power and sonication time were found best for Cy3-gal extraction.•Cy3-gal concentration was found significantly higher ...under UAE compared to CE.•Viscosity of the extract had a negative impact on Cy3-gal extraction yield.•Batch scale-up UAE of Cy3-gal was found significantly better than continuous process.
Ultrasonic effect on extraction of cyanidin-3-galactoside (Cy3-gal) from pear fruit peel was investigated and compared with conventional extraction (CE) method. Different process factors were tested to determine the optimum conditions for ultrasonic-assisted extraction (UAE). Results revealed that under optimized UAE conditions (ultrasonic power = 162 W, temperature = 71 °C, trifluoroacetic acid = 3%, ethanol = 57%, ultrasonication time = 11 min, and sample to solvent ratio = 1:30 g/ml), Cy3-gal yield was significantly higher (0.34 3± 0.005 mg/g) than from CE (0.266 ± 0.004 mg/g), whereas the extract viscosity during UAE showed a negative impact. UPLC-Triple-TOF/MS analysis detected a total number of 13 anthocyanin compounds, out of which 8 were identified and that mainly consisted of cyanidin, delphinidin and petunidin compounds. Higher yield of Cy3-gal under UAE compared to CE was also justified by higher deformations in the cell structure. The possible mechanism of ultrasonication effect during the extraction process is also proposed in the present study. During scale-up UAE process, the extraction yield of Cy3-gal was recorded higher under batch scale-up compared to continuous operation. The present study is an attempt to optimize UAE of valuable anthocyanins from Pyrus communis ‘Starkrimson’ fruit peel and further scaled-up for higher volume extraction which can be utilized for industrial applications.
In this study, the mechanism recruited by exogenous melatonin application at 100 μM for alleviating chilling injury in tomato fruits during cold storage was investigated. Alleviating chilling injury ...in tomato fruits in response to exogenous melatonin application at 100 μM may ascribe to providing sufficient intracellular ATP occur by higher H-ATPase, Ca-ATPase, cytochrome c oxidase (CCO), and succinate dehydrogenase (SDH) enzymes activity during cold storage. Also, higher unsaturated/saturated fatty acids (unSFA/SFA) ratio owing to higher linoleic and linolenic acids accumulation coincides with lower palmitic, stearic and oleic acids accumulation may be responsible for alleviating chilling injury in tomato fruits in response to exogenous melatonin application at 100 μM, which may occur by higher
fatty acid desaturase 3
and
7
(
FAD3
and
FAD7)
genes expression accompanying by lower
phospholipase D (PLD)
and
lipoxygenase (LOX)
genes expression and enzymes activity, in addition to providing sufficient intracellular ATP. Therefore, exogenous melatonin application may be a beneficial postharvest procedure for alleviating chilling injury in tomato fruits during cold storage.
•Exogenous sucrose delayed the decrease of sucrose content in strawberry fruit.•Sucrose treatment increased glucose and fructose content by promoting AI activity.•Sucrose treatment accelerated the ...accumulation of four pelargonidin derivatives.•Four pathways involved in anthocyanin synthesis were activated by sucrose signal.
Sucrose acts as a vital signal that modulates fruit ripening. In current study, 50 mM sucrose was applied in strawberry fruit to investigate the regulation of sucrose in anthocyanin synthesis after harvest. The results showed that sucrose treatment increased the contents of glucose, fructose and sucrose, which were 19.76%, 15.83% and 16.50% higher, respectively, compared with control at the end of storage. The increase of glucose and fructose contents resulted from the activation of acid invertase by sucrose treatment. In addition, sucrose treatment specifically increased four pelargonidin derivatives, pelargonidin 3-glucoside, pelargonidin 3-rutinoside, pelargonidin 3-malonylglucoside and pelargonidin 3-methylmalonyglucoside, during the storage. Further, transcriptional profiles and enzyme activities analysis revealed that the accumulation of pelargonidin derivatives was related to the activation of the pentose phosphate pathway, shikimate pathway, phenylpropanoid pathway, and flavonoid pathway. These results provided new insights into the regulation of sucrose on the accumulation of individual anthocyanins.
•The LBL electrostatic deposition maintained strawberry firmness and volatile aroma.•The LBL coating inhibited some primary metabolism in strawberry.•Special secondary metabolites in LBL coated ...strawberry were reduced after storage.
Postharvest strawberries (Fragaria × ananassa Duch.) were coated either by the layer-by-layer (LBL) electrostatic deposition, based on chitosan and carboxymethyl cellulose (CMC), or coated by 1% chitosan. Results suggested that LBL edible coating was significantly effective at inhibiting the loss of fruit firmness and aroma volatiles of strawberry, with little effect on the total soluble solids and total acidity contents. Through an untargeted metabolomic analysis, we found that the LBL application significantly reduced the primary metabolite contents involved in carbohydrate, fatty acids and amino acids metabolism, as well as the secondary metabolite contents involved in terpenoid, carotenoid, phenylpropanoid and flavonoid metabolism after storage. Our results indicated that the LBL edible coating could be potential to maintain strawberry quality with lower metabolites contents after eight days of storage.
Fungal infections significantly alter the emissions of volatile organic compounds (VOCs) by plants, but the mechanisms for VOCs affecting fungal infections of plants remain largely unknown. Here, we ...found that infection by Botrytis cinerea upregulated linalool production by strawberries and fumigation with linalool was able to inhibit the infection of fruits by the fungus. Linalool treatment downregulated the expression of rate-limiting enzymes in the ergosterol biosynthesis pathway, and this reduced the ergosterol content in the fungi cell membrane and impaired membrane integrity. Linalool treatment also caused damage to mitochondrial membranes by collapsing mitochondrial membrane potential and also downregulated genes involved in adenosine triphosphate (ATP) production, resulting in a significant decrease in the ATP content. Linalool treatment increased the levels of reactive oxygen species (ROS), in response to which the treated fungal cells produced more of the ROS scavenger pyruvate. RNA-Seq and proteomic analysis data showed that linalool treatment slowed the rates of transcription and translation.
► Chilling injury promoted polyphenol oxidase (PPO) and peroxidase (POD) activities and polyamine content of ‘Qingnai’ plums during cold storage. ► Salicylic acid (SA) suppressed chilling injury of ...‘Qingnai’ fruit. ► Chilling injury suppression was associated with delayed PPO and POD activities, and enhanced polyamine accumulation.
The effects of salicylic acid (SA) treatment on chilling injury, disease incidence, electrolyte leakage, malondialdehyde (MDA) content, respiration rate and ethylene production, polyphenol oxidase (PPO) and peroxidase (POD) activities, and polyamine (PA) content of ‘Qingnai’ plum fruit were examined. Chilling injury, disease incidence, electrolyte leakage, MDA content, respiration and ethylene production of control fruit increased after about 15–30
days cold storage. Chilling injury promoted PPO and POD activities which were associated with fruit flesh browning. Accompanied by a polyamine content increase, chilling injury was positively correlated with putrescine and spermine contents in control fruit. Suppression of chilling injury by SA was associated with reducing leakage, MDA content, delayed activities of PPO and POD, and enhanced PA accumulation. SA treatment delayed the onset of the climacteric peak of respiration, and also inhibited respiration and ethylene production. The results suggest that SA treatment may be used commercially to control chilling injury in ‘Qingnai’ plum fruit during cold storage.
Major losses of fresh horticultural produce transpire during postharvest storage due to prompt senescence and diseases. The traditional postharvest preservation techniques used after harvest are ...based on cooling and the application of chemical preservation techniques. As a residue-free physical sterilization and preservation method, light-emitting diode (LED) treatment, has recently been applied for postharvest storage of fruits and vegetables by numerous researchers. This paper reviews the recent applications of LEDs in postharvest storage of fresh produce, including its effect on physiological characteristics, secondary metabolism, nutritional attributes, ripening process, senescence, shelf-life improvement, and pathogenic microbial spoilage of fruits and vegetables. LED treatment has promoted the accumulation of different phytochemicals, such as phenolic compounds, vitamins, glucosinolates, chlorophyll, total soluble solids, and carotenoids. Changes in the nutritional content, anthocyanin content, antioxidant capacity, and ripening were also observed after the treatment. Reduction in microbial spoilage and delay senescence were evident after the LED exposure. The influence of LED light depended on the fruit and vegetable variety. Therefore, LED treatment is an efficient and promising strategy for extending the storage life of fruits and vegetables with enhanced nutritional values.
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