100 research outputs found
Emerging technologies for safe, healthy and sustainable fresh-cut produce
No full textIn the last decade the food market has experienced the establishment of products meeting consumer needs of healthy commodities with improved fresh-like appearance and convenience. In this context, fresh-cut fruit and vegetables combine their fresh-like and healthy characteristics with a minimal time of preparation before consumption. Fresh-cut produce is thus a growing sector and there are still large opportunities for further development and improvement both at industrial level and in market shares. Appropriate solutions could overcome the critical aspects regarding product safety, quality and shelf life, production costs and environmental impact. In particular, suitable techniques should be employed to increase fresh-cut produce safety, affected by both chemical and microbiological contaminations. In addition to the latter, plant senescence together with enzymatic reactions should be controlled in order to guarantee product quality and extend the shelf life. Furthermore, proper technologies could be exploited to reduce the production costs and the environmental load of these produce. To this regard, process optimization as well as the implementation of novel technologies, could decrease energy, water and chemical compounds consumption, making fresh-cut production more sustainable in terms of economical, ethical and environmental aspects.
Driven by these needs from the fresh-cut production chain, a partnership among 8 Italian universities and research centres investigated the entire fresh-cut production chain from farm to fork. The project "AGER 2010 2370 Stayfresh: Novel strategies meeting the needs of the fresh-cut vegetable sector" aimed to find out integrated solutions able to optimize and innovate the fresh-cut produce from the agronomic aspects up to the ready-to-eat product.
This PhD thesis is therefore part of the abovementioned wide project and aimed to investigate whether selected novel non-thermal technologies can be exploited to enhance safety, quality and sustainability of fresh-cut produce, such as lettuce, apple and potato. The research was divided in two parts and the attention was focused on two processing steps, namely washing and stabilization treatments, which are critical in fresh-cut production. In the first part of the work, the application of promising novel technologies such as electrolyzed water and light technologies (i.e. UV-C and pulsed light) were studied as alternatives to highly chlorinated solutions to avoid cross-contamination during fresh-cut lettuce washing, guaranteeing product hygienic quality as well as the reduction of chlorinated compounds, water use and wastewater discharges. The second part addressed to fruit and vegetables stabilization by studying the effect of light technologies, dense phase carbon dioxide and pulsed electric fields. The latter were considered as potential techniques for microbial decontamination, enzymatic inactivation and quality enhance of fresh-cut lettuce, apple and potato. In particular, the experimental work regarding the application of pulsed electric fields on potato cubes was performed at the Laboratory of Food Technology of the UCD School of Agriculture and Food Science, Dublin, Ireland
Philosophical Thought and Life of Ignat Abdiralovich
No full textРазгледжаны жыццё і творчасць Ігната Канчэўскага (Абдзіраловіча) – аўтара знакамітага эсэ «Адвечным шляхам».The life and work of Ignat Kanchevsky (Abdiralovich), the author of the famous essay «Eternal way», is examined
Efficient management of the water resource in the fresh-cut industry: Current status and perspectives
No full textAmong the different food industries, fresh-cut produce manufacturing is one of the major water-intensive, due to the huge consumption of potable water to perform washing operations required to guarantee the safety and quality of the product. Reducing the water footprint of washing is thus a challenge for fresh-cut industries and food researchers. This review paper examines the current status of the water resource management in the fresh-cut industry and critically describes a comprehensive approach to the improvement of the water use efficiency by implementing strategies of water recirculation, reuse and recycling. In particular, advantages and limitations of chlorine and chlorine-free disinfectants to reduce water turnover in washing tanks were considered. In addition, particular attention was focussed on innovative technological solutions, based on either physical or chemical stresses, which could be exploited individually or in combination to treat wastewater deriving from fresh-cut washing and allow its recycling within the processing plant. © 2015 Elsevier Lt
Water saving in fresh-cut salad washing by pulsed light
No full textThe possibility to wash salad with recycled water submitted to pulsed light decontamination was studied. Wastewater deriving from lamb's lettuce washing was exposed to pulsed light at increasing fluence up to 17.5 kJ/m2. Pulsed light dose of 11.0 kJ/m2 allowed the inactivation of most of the native microflora and the achievement of more than 6-Log reductions in inoculated microorganisms (Salmonella enterica, Listeria monocytogenes and Escherichia coli). The increase in washing cycles up to 5 did not impair the efficacy of wastewater decontamination promoted by pulsed light (circa 4-Log reduction in native microflora) nor the hygienic level of the washed salad (circa 1-Log reduction in native microflora). Industrial relevance The application of pulsed light to decontaminate wastewater deriving from salad washing could decrease the water footprint of fresh-cut vegetables by minimising the overall requirement for water in industrial plants. In addition, it would decrease the risk for residuals of toxic chemicals in fresh-cut vegetables by avoiding the use of sanitizers, such as chlorine. © 2015 Elsevier Ltd. All rights reserved
Effect of dense-phase CO2 on polyphenoloxidase in model solutions
No full textThis paper was addressed to investigate
polyphenoloxidase structural changes in model
solutions upon inactivation by DP-CO2 treatments.
Polyphenoloxidase was chosen as a typical example of
an enzyme responsible for food quality decay. Mushroom
polyphenoloxidase was exposed at room temperature
for 5 min to DP-CO2 treatments at increasing
pressure up to 12 MPa in order to obtain samples with
decreasing residual activity. Samples having decreasing
residual polyphenoloxidase activity were also prepared
by thermal inactivation at 50 °C for up to 30 min.
Molecular changes in polyphenoloxidase structure
upon DP-CO2 and thermal inactivation were studied
by HPLC gel permeation
Surface decontamination of fresh-cut apple by pulsed light: Effects on structure, colour and sensory properties
No full textThe effect of pulsed light at increasing fluence (17.5, 52.5, 105.0 and 157.5 kJ/m2) was studied with
reference to germicidal efficiency and changes in fresh-like appearance of sliced apple. Independent
of fluence, viable counts and inoculated bacteria were reduced by 1 and 3 logs respectively. Fluence
significantly affected weight loss, colour and sensory attributes of apple slices during storage at 6 ◦C.
Pulsed light at 17.5 kJ/m2 resulted in apple slices comparable to the untreated samples, with limited
quality changes. By contrast, at higher fluence, apple slices underwent dehydration and browning due to
loss of cell integrity. Exposure to high fluence treatments was also associated with negative changes in
the flavour profile of sliced apple during storage
Cheese fortification using saturated monoglyceride self-assembly structures as carrier of omega-3 fatty acids
No full textThe purpose of this research was to study the capacity of emulsions containing saturated monoglyceride self-assembly structures to deliver omega-3 fatty acids in fresh soft cheese. To this aim, fortified emulsions containing different ratios of milk, saturated monoglycerides (MGs) and cod liver oil were added to milk before cheese-making. These emulsions were characterised by distinct microstructural features observed by polarised light microscopy and apparent viscosity values. The omega-3 delivery performance of MG emulsions highlighted that this strategy allowed a good retention of the omega-3-rich oil in the curd (up to 75%). The fortified cheeses showed yield value and fat content higher than those of control samples. The enriched cheese showed hardness and cohesiveness obtained by texture profile analysis similar to those of the unfortified product. Only a slight decrease in gumminess was detected in fortified cheese. © 2015 Institute of Food Science and Technology
Milk pre-treatment by high pressure homogenization in the manufacturing of "queso fresco" fortified with omega-3 fatty acids
No full textThe aim of this study was to evaluate the feasibility of high pressure homogenization (HPH) as milk pre-treatment in the process of manufacturing cheese fortified with omega-3 fatty acids. Raw milk was fortified with animal and vegetable sources of omega-3 fatty acids and homogenized at increasing pressure from 20 to 100 MPa. Treated milk was then used to prepare queso fresco, a soft and fresh Hispanic cheese. Cheese yield, moisture, fat content, and texture were evaluated after processing. The development of oxidation was also monitored during cheese storage at 4 degrees C for up to 21 days. Pressure higher than 50 MPa was necessary to effectively incorporate omega-3 fatty acids in cheese and at the same time to reduce the quantity of oil lost in the whey. Homogenization treatments caused cheese quality attribute changes due to modifications induced by HPH process on native structures of milk. Cheeses obtained with homogenization showed higher moisture and yield and lower fat content than untreated cheeses. A decrease of texture parameters was also observed for homogenized samples. The source of omega-3 did not affect the cheese quality attributes
Minimization of water consumption in fresh-cut salad washing by UV-C light
No full textThe decontamination effect of UV-C light at increasing fluence up to 1.2kJ/m2 was studied with reference to natural microflora and inoculated pathogens in lamb's lettuce wash water. UV-C light dose of 0.4kJ/m2 allowed to inactivate most of the native microflora and to achieve more than 5- Log-reductions in inoculated microorganisms (Salmonella enterica, Listeria monocytogenes and Escherichia coli). In multiple washing cycles up to 5, UV-C light treatment allowed to obtain more than 3-log reductions in native microflora in wash water. Spectral properties indicated that, independently on the number of recycling cycles, a considerable amount of UV-C light can penetrate wash water if its thickness is lower than circa 1cm. © 2014
Effect of pulsed light on total microbial count and alkaline phosphatase activity of raw milk
No full textThe effect of pulsed light (PL) treatments at increasing fluence (0.26-26.25Jcm-2) on total microbial count and inactivation of alkaline phosphatase (ALP) in raw whole milk was investigated. High fluence resulted in a 3.2 log reduction in total microbial count and about 94% inactivation of ALP; concomittantly, milk temperature increased to 55°C. To determine the photochemical effect of PL treatment only, samples were equilibrated at 0°C before being exposed to high fluence; this gave a milk temperature of 27°C, a 1.53logcfumL-1 microbial reduction and 44% inactivation of ALP. The effect of temperature increase was determined by heating at 55°C for 60s or at 59°C for 70s; only the latter yielded a slight reduction in microbial count and ALP activity. This indicated a combined effect between photochemical and photothermal damage for inactivation of both natural microflora and ALP. © 2014 Elsevier Ltd
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