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Despite their high nutritional value, high quantities of fish caught in the Adriatic Sea are underused or discarded for their insignificant economic value. Mechanical separation of flesh represents an opportunity for developing innovative semi-finished products, even if it can promote an increased quality degradation rate. The aim of this study was to evaluate physico-chemical modifications of mechanically separated mantis shrimp flesh during deep-freezing storage. Flesh samples obtained using a belt-drum separator, frozen and vacuum-packed, were stored at 3 temperatures (industrial: &minus, 26 &deg, C, domestic: &minus, 18 &deg, C and abuse: &minus, 10 &deg, C) for 12 months. During storage, qualitative (color, water content, pH, fatty acids (FA) and lipid oxidation) were evaluated. Fish freshness parameters (e.g., trimethylamine (TMA), dimethylamine (DMA) and amino acids) were assessed using nuclear magnetic resonance (1H-NMR). The mechanical separation process accelerated the initial oxidation phenomena, promoting color alterations, compared to manual separation. The main degradation phenomena during storage were significantly affected by temperature and were related to changes in luminosity, oxidation of n-3 polyunsaturated fatty acids (PUFA), increased lipolysis with release of free FA, production of TMA and DMA by residual enzymatic activity, and changes in amino acids due to proteolysis. The inter-disciplinary approach permitted important findings to be made, in terms of the extent of different degradative phenomena, bound to processing and storage conditions of mechanically separated mantis flesh.

The aim of this work was to evaluate the effect of pulsed electric field (PEF) pre-treatment on mass transfer phenomena, water distribution and some physico-chemical parameters of osmo-dehydrated organic strawberries. For PEF treatments 100 near-rectangular shaped pulses, with fixed pulse width of 100 μs and repetition time of 10 ms were used. Electric fields strength applied were 100, 200 and 400 V cm−1. Afterwards, samples were subjected to OD treatments carried out in two different hypertonic solutions (40% w/w), one with sucrose and the other one with trehalose. The results shown that PEF treatment positively affected the mass transfer during OD even at the lowest electric field strength applied (100 V/cm), partially preserving the cell viability and maintaining at the same time the fresh-like characteristics of strawberries.

The evaluation of fish freshness can be performed using chemical, sensory and physical methods. Besides sensory methods, several instrumental techniques have been applied with the objective of replacing sensory assessment. The aim of this study was to set up and test objective physical methods mainly based on computer vision system (CVS) to assess red mullet (Mullus barbatus) freshness evolution during 10 days of storage, at two different storage temperatures (0 and 4 °C). To check the effectiveness of the purposed physical methods, CVS features (loss in the epidermis pigmentation, development of gill mucus and eye concavity index) and firmness have been compared with chemical trimethylamine content and sensory (QIM) attribute scores. As expected, fish degradation was faster at the higher temperature. Instrumental texture evaluation of fish by penetration test enabled to detect distinctive firmness changes due to onset and resolution of rigor mortis, and the successive tenderization phenomenon. Among CVS parameters, the epidermis pigmentation loss, and particularly the eye shape modification (eye concavity index) evidenced a high sensibility for the estimation of fresh red mullet quality loss, as a function of the two different storage conditions, and a good agreement with trimethylamine content and QIM response evolution.

In the present study, a green tea extract (GTE) was used to enrich minimally processed apples by vacuum impregnation VI in order to obtain a nutritionally fortified product. Apples were impregnated with isotonic sucrose solutions containing 1% GTE and/or 1% ascorbic acid (AA). The impact of GTE enrichment on quality characteristics of the product, stability of the antioxidant compounds and activity during refrigerated storage were assessed. Results showed that a satisfactory impregnation of minimally processed apples was achieved and resulted in a strong increase of the antioxidant compounds content and activity. While other qualitative parameters were only slightly affected, colour of samples was influenced just after the VI treatment with an increase of the yellow/orange colour components but also during storage with a higher degree of browning development. However, the addition of 1% of AA allowed to better preserve colour and antioxidant properties during storage limiting oxidative phenomena. Industrial relevance The demand for functional foods characterized by a high nutritional value is constantly increasing. Vacuum impregnation (VI) is a technology that allows the replacement of the gas into the porous food structure with an aqueous solution, promoting compositional changes in short treatment times thus permitting the direct formulation of a porous food matrix, hence representing a promising technology for product innovation for the fruit and vegetable industry. Green tea (GT) is a high source of flavanoids, known to have strong antioxidant properties which has been widely studied both in in-vitro and in-vivo trials. According to the results obtained in this study, the enrichment of apples with GT catechins and AA seemed to be promising in order to obtain a nutritionally fortified fruit product.

This research aims to evaluate the effect of pulsed electric field (PEF) pre-treatment for osmotic dehydration (OD) on physiological changes in organic strawberries and kiwifruits, in terms of metabolic heat production, measured by isothermal calorimeter, and of tissue damage, evaluated by fluorescence microscopy, texture analysis, and electrolytes leakage. Fruits were pre-treated at two electric field strengths (100 and 200 V/cm) using 100 near-rectangular shaped pulses (pulse width: 10 μs, repetition time: 10 ms) and then subjected to OD in hypertonic solutions (40% w/w) of sucrose or trehalose, both added with calcium lactate 1%. Results showed that OD alone allowed to retain the functionality of the membranes causing only a decrease in the endogenous heat production. The application of low electric field strength (100 V/cm) generally preserved the cell viability, which was drastically reduced after OD treatment. On the contrary, the application of 200 V/cm caused tissue damage and loss of cell vitality, probably due to irreversible electroporation. Industrial application PEF could be an interesting pre-treatment for reducing the intensity of osmotic dehydration of fruits. However, it is important to understand the implication of the treatment on the tissue metabolism and structure to control the effect on the quality of the final product. This study provides some useful information that could be exploited for the industrial production of intermediate moisture fruit products.

Candied wumei fruit (Prunus mume) is a traditional product in Eastern Asian countries generally obtained by a long osmotic dehydration (OD) process. This study evaluated the effect of the application of high hydrostatic pressure (HHP) and heating pre-treatments to accelerate the OD process on some bioactive compound content, antioxidant activity, and volatile profile of wumei fruit. Whole fruits were subjected to HPP treatment (50MPa for 1min) and heating (100°C for 1min) and then to OD in a 40% sucrose solution for 5days. Results showed that both heating and HPP pre-treatment increased mass transfer in a comparable way; however, HPP allowed a significant higher retention of antioxidant compounds and activity compared with the heating treatment, resulting in similar values to the untreated product. Moreover, HPP promoted the release of various volatile components resulting in a richer volatile profile compared with both control and heat-treated samples. Hence, HPP showed good potentiality as an alternative non-thermal pre-treatment for the production of candied wumei fruit characterized by high nutritional and sensorial properties.

Over the past several decades, as a result of the increasing growth rate and body size of modern hybrid birds, poultry industry has been facing up the occurrence of many breast meat abnormalities, such as White Striping (WS), Wooden Breast (WB) and Spaghetti Meat (SM), whose incidence has recently reached alarming levels. Thus, the present study aimed at simultaneously investigating the implications of WS, WB and SM abnormalities on meat colour, pH, proximate composition, fatty acid profile, collagen, thermal properties as well as texture and water mobility, assessed on both superficial and deep section of Pectoralis major muscle. Overall, the occurrence of breast abnormalities is associated with a higher ultimate pH and a significant increase in moisture and fat level, coupled with a decrease in protein and ash content with WB showing the most detrimental effect. However, fatty acid profile resulted to be mildly modified only by WS. Moreover, WB fillets showed significantly higher (P

The present work aims to study the effects of cold gas plasma on some quality parameters of apple slices belonging to four different cultivars (Pink Lady®, Fuji, Red Delicious and Modi®), with particular attention to polyphenoloxidase (PPO) inhibition and related changes in colour and visual quality. Upon plasma exposure a noticeable reduction of superficial browning was observed in all cultivars but not always proportionally to treatment time; the effect on PPO activity was very variable and not correlated to the effect on enzymatic browning. Textural parameters were affected by plasma treatments only in Red Delicious apples. Generally, the response of the tissue to the treatments was variable according to the cultivar considered. The results obtained in this study indicate the necessity of further investigation about consequences of plasma treatment on specific tissue physiology in order to choose the better treatment parameters, optimizing its effect for the specific final product. Industrial relevance The application on cold plasma to minimally processed fruit and vegetable has shown a good potential for enzymatic browning inhibition making it an interesting alternative to traditional dipping methods. Nevertheless, the effect on the tissue to the exposure to plasma active particles is not fully known yet. For the industrial application of the treatment, the response for example of different cultivars to the treatment is of high importance, in the first place for the selection of the more appropriate raw material but also to eventually adapt the process parameters to the specificity of the matrix.

Pulsed electric field (PEF) is a non-thermal technology which is increasingly drawing the interest of the meat industry. This study aimed at evaluating the effect of PEF on the main technological properties of chicken meat, by investigating the role of the most relevant process parameters such as the number of pulses (150 vs. 300 and 450 vs. 600) and the electric field strength (0.60 vs. 1.20 kV/cm). Results indicated that PEF does not exert any effect on meat pH and just slightly affects lightness and yellowness. Low-intensity PEF treatments improved the water holding capacity of chicken meat by significantly (p &lt, 0.001) reducing drip loss up to 28.5% during 4 days of refrigerated storage, without damaging proteins&rsquo, integrity and functionality. Moreover, from the analysis of the process parameters, it has been possible to highlight that increasing the number of pulses is more effective in reducing meat drip loss rather than doubling the electric field strengths. From an industrial point of view, the results of this explorative study suggested the potential of PEF to reduce the undesired liquid inside the package, thus improving consumer acceptance.

The changes in moisture adsorption isotherms of commercial biscuits during storage were investigated by means of a rapid Dynamic Dewpoint Isotherms (DDIs) method. Moreover, the relationships between the changes in moisture content and some quality characteristics of biscuits (moisture, aw, peroxide value - PV and texture) were studied during 92 days of storage at 35 °C. GAB model was used to fit the experimental sorption behaviours. During storage, moisture content and aw of biscuits increased and the obtained isotherms showed modifications in behaviour and shape. Significant changes were observed in PV values and texture, particularly during the first 40 days of storage. The monolayer moisture content, obtained by the BET equation, significantly increased during storage from 1.473 to 2.080 g water 100 g db(-1), probably because of the increase in the active sites for water binding due to the chemical and physical changes of the main components, induced by product ageing.

The aim of this study was to evaluate the effect of gas plasma treatment on fresh-cut melon stability during controlled storage. Plasma treatments of 15 + 15 and 30 + 30 min were conducted on fresh cut melon using a dielectric barrier discharge (DBD) generator. Samples were packed and stored for 4 days at 10 °C and evaluated for qualitative, metabolic and microbiological indexes. Qualitative parameters of fresh-cut melon (titratable acidity, soluble solid content, dry matter, colour, texture) were only weakly affected by plasma treatment. Peroxidase (POD) and pectin methylesterase (PME) activities were slightly inhibited by the treatment up to respectively about 17 and 7%. Tissue metabolic heat production decreased proportionally to the treatment duration, while a partial conversion to anaerobic metabolism was observed. Microbial results showed that a significant increase in microbial shelf-life was achieved following the 15 + 15 min plasma treatment due to a delayed growth of spoilage mesophilic and psychrotrophic microflora. Industrial relevance The demand for fresh-cut products characterized by high qualitative and nutritional values and an acceptable shelf-life has promoted the research for non-thermal treatments. Fresh-cut melon is considered to be highly perishable and potentially hazardous food because it can support the growth of spoilage microflora and several pathogens. Cold plasma has shown its potentiality as an antimicrobial treatment and has been tested on different food products, but the impact on product quality and metabolism is still scarcely known. The results obtained in this study contributed to deepen the knowledge on the effect of plasma treatment on microbial, qualitative and metabolic aspects of fresh-cut melon.

The most commonly used method for fish freshness determination is the sensory inspection; alternative sensory methods such as the Quality Index Method (QIM), based on the significant sensory parameters of one specific species, have been recently suggested. Considering that most of the sensory parameters are based on chromatic and morphological visual impression, the set-up of an objective method using computer vision techniques is very promising. The objective of this research was to characterize the changes in eye chromatic and morphological characteristics of European hake (Merluccius merluccius) during 13 days of storage on ice, using a tailored computer vision technique and a 3D scanner. Results obtained by multivariate statistical analysis of the colour spectra of eye images and by the eye concavity index using a 3D scanner permitted to estimate fish unacceptability after 7 days of storage, in agreement with results obtained by QIM sensory analysis. Moreover, 1H NMR was used to evaluate the production of trimethylamine (TMA) and the Ki index, confirming a good correlation with eye chromatic and morphological features. This preliminary study showed the high potentiality of the developed method as a non-destructive technique for raw fish freshness characterization / prediction, being a promising approach to create a robust portable instrument for the evaluation of fish freshness in real transport and marketing conditions.

Induced crystallization is carried out by adding fine crystals to the liquid honey in order to increase the rate of the process and to obtain a uniform and stable product. The aim of this research was to describe the kinetic of crystallization of honey and the evolution of its physical properties on the basis of different fructose/glucose ratio. To three honey samples selected on the basis of increasing fructose/glucose ratios, 5% of fine crystals have been added, before storage at 14 °C until complete crystallization. During storage, kinetic of crystallization were determined by differential scanning calorimetry and microstructure by a polarising microscope. Moreover, variations of water activity, colour and texture parameters were evaluated during storage. The Avrami equation was found to well describe the crystallization kinetic, although the relation of the Avrami parameters with the nucleation and crystal growth is not entirely clear. The composition of honey was found to influence not only the rate of crystallization, but also the qualitative parameters of sample texture and colour, leading to more pronounced changes during honey storage as the amount of crystallized glucose increased.

Osmotic dehydration (OD) is the most important procedure for producing candied green plums. This study investigated high hydrostatic pressure treatment (HHP) to improve OD process. Central composite design was applied to optimize HHP parameters with pressure ranging from 50 to 400 MPa and time from 1 to 30 min. Innovative HPP procedure was compared with traditional heating treatments on the acceleration efficiency by Peleg’s model. The physico-chemical and sensorial properties were compared. The results showed that HHP was effective to accelerate the OD process, but was not as efficient as heating methods. HHP promoted higher titratable acid content, firmness and greener color than heating on the obtained product. Sensory results revealed that HHP allowed to better preserve the typical odor and flavor of the final products. Generally, HHP treatments show high potentiality to improve the OD performances of candied green plums, together with the overall quality of the final product. Practical applications: Candied green plum is a popular snack in Eastern Asian countries. The traditional process includes a heating assisted treatment in order to accelerate the candying progress, which may induce decrease to the quality of the final product. Non-thermal high hydrostatic pressure could improve the osmotic dehydration process performances, minimizing the thermal damages on the final products, promoting the improvement of its overall quality.

Cold atmospheric plasma (CAP) has shown good potentiality for the decontamination and stabilization of fresh fruit and vegetable products, however, information about its effect on nutritional quality is still scarce. The aim of this research was to evaluate the impact of a form of indirect treatment known as Dielectric Barrier Discharge (DBD) on apple slices&mdash, more specifically, the polyphenolic profile and antioxidant activity of fresh-cut Pink Lady apples. Atmospheric plasma was generated using air as feed gas, and directed to apple slices for up to 30 min. The effect of plasma treatment on physico-chemical parameters was mainly observed as a slight acidification of the tissue and reduction of browning after an extended period of exposure. The samples&rsquo, phenolic profile was significantly affected after 10 min of treatment, both in quantitative (an approximately 20% increase) and qualitative terms, while with increasing exposure time a progressive decrease of all polyphenol classes was observed. The antioxidant activity, evaluated by different in-vitro methods, followed a similar trend, increasing after 10 min of processing and then decreasing. Results highlighted how plasma exposure promotes a metabolic response of the fresh tissue, and the importance of carefully controlling the exposure time in order to minimize the loss of nutritional properties.

Made available in DSpace on 2018-12-11T17:10:06Z (GMT). No. of bitstreams: 0 Previous issue date: 2017-05-01 The influence of the addition of calcium lactate (CaLac) and ascorbic acid (AA) to sucrose (Suc) osmotic solutions on osmotic dehydration kinetics and endogenous metabolic heat production of apple tissue was evaluated. Our research goal was to characterize mass transfer and endogenous metabolic phenomena of the tissue to obtain minimally processed apples. The presence of CaLac and AA in solution affected the mass transfer of water and solutes, which was attributed to the changes in the cellular structure and thus to spaces available for solute transport. The metabolic heat production in samples treated in sucrose solutions was slightly lower than in untreated samples, and it was further reduced with CaLac addition. However, samples impregnated with AA exhibited a higher heat production due to a metabolic response of the tissue to AA treatment. When combined with CaLac, the heat production decreased to a level lower than untreated samples, except for those that were treated for 120 and 240 min (higher impregnation), achieving the highest heat production values. These results confirm previous findings, suggesting that AA solution can promote a stress response on specific fresh-cut vegetable tissues, as well as an increase of their endogenous metabolic activity, as confirmed by the higher O2 consumption observed with the head space gas determination. Department of Agricultural and Food Sciences University of Bologna Department of Food Engineering and Technology São Paulo State University (UNESP), São José do Rio Preto Interdepartmental Centre for Agri-Food Industrial Research University of Bologna Department of Food Engineering and Technology São Paulo State University (UNESP), São José do Rio Preto

The effects of the addition of calcium lactate and ascorbic acid to sucrose osmotic solutions on cell viability and microstructure of apple tissue were studied. In addition, water distribution and mobility modification of the different cellular compartments were observed. Fluorescence microscopy, light microscopy and time domain nuclear magnetic resonance (TD-NMR) were respectively used to evaluate cell viability and microstructural changes during osmotic dehydration. Tissues treated in a sucrose-calcium lactate-ascorbic acid solution did not show viability. Calcium lactate had some effects on cell walls and membranes. Sucrose solution visibly preserved the protoplast viability and slightly influenced the water distribution within the apple tissue, as highlighted by TD-NMR, which showed higher proton intensity in the vacuoles and lower intensity in cytoplasm-free spaces compared to other treatments. The presence of ascorbic acid enhanced calcium impregnation, which was associated with permeability changes of the cellular wall and membranes.

Pulsed electric field (PEF) treatments can induce metabolic stress responses in plant tissue as a function of the applied conditions. This study highlighted the metabolic effects of reversible and irreversible electroporation in fresh-cut apple tissue, by adjusting the electric field strength to 100, 250 and 400 V/cm (100 μs pulse width, 60 pulses, 100 Hz). Metabolic heat, O 2 and CO 2 gas analysis, along with metabolomics, were employed to jointly evaluate the PEF-induced effects after 24 h at 10 °C. Marked metabolic changes were registered when the threshold of irreversible electroporation was exceeded, at 250 and 400 V/cm. With such treatments, a drop of metabolic heat and respiration rate was observed, as a probable consequence of the loss of the cell viability, anaerobic respiration pathways were noticeably lowered, while γ-aminobutyric acid metabolism was activated. Conversely, minimal modifications of the metabolism heat and metabolites concentrations were noticed when 100 V/cm was applied. Industrial relevance Metabolic response of fresh-cut fruit and vegetables as function of the manufacturing process is a fundamental aspect directly related to the quality of the final products. Pulsed electric fields (PEF), as well as other innovative technologies, can induce undesired effects on tissue metabolism that might limit the industrial application. Furthermore, the analytical methods used in the present work provide useful tools for the optimization of the PEF treatment conditions for fresh-cut manufacturers.