Evaluation of the use of probiotic acid lactic bacteria in the development of chicken hambúrguer

The objective of this study was to investigate the effect of fermentation with Lactobacillus acidophilus CRL 1014 on the physicochemical, microbiological and sensory characteristics of a hamburger product like processed with chicken meat and okara flour, with reduction of curing salts. A mixture of ingredients containing 90% chicken meat and 10% okara flour was subjected to the following treatments: F1: fermented with Lactobacillus acidophilus; F2:75 mg nitrite/kg and fermented with Lactobacillus acidophilus; F3: 150 mg nitrite/kg and unfermented. The quality of the “hamburgers” was assessed by physical and chemical analysis (pH, cooking yield and shrinkage), chemical composition, microbiological tests (Salmonella spp., count of sulphite-reducing clostridia, staphylococos coagulase-positive, total coliforms and Escherichia coli) and sensory analysis (sensory acceptance and purchase intent). During the first six days of fermentation, there was a decrease in pH from approximately 6.33 to 5.10. All the samples showed the same chemical composition (p < 0.05). The fermentation process was observed to inhibit the multiplication of microorganisms of several groups: coagulasepositive staphylococci, sulphite-reducing clostridia, Salmonella spp. and E. coli. The different “hamburgers” formulations showed high scores for all the sensory attributes evaluated, without differing from each other (p < 0.05). The results showed that the use of L. acidophilus CRL 1014 enabled the production of a safe product, with good physicochemical and sensory characteristics, in the absence of curing salts.

Evaluation of rhamnolipid and surfactin to reduce the adhesion and remove biofilms of individual and mixed cultures of food pathogenic bacteria

Biofilms represent a great concern for food industry, since they can be a source of persistent contamination leading to food spoilage and to the transmission of diseases. To avoid the adhesion of bacteria and the formation of biofilms, an alternative is the pre-conditioning of surfaces using biosurfactants, microbial compounds that can modify the physicochemical properties of surfaces changing bacterial interactions and consequently adhesion. Different concentrations of the biosurfactants, surfactin from Bacillus subtilis and rhamnolipids from Pseudomonas aeruginosa, were evaluated to reduce the adhesion and to disrupt biofilms of food-borne pathogenic bacteria. Individual cultures and mixed cultures of Staphylococcus aureus, Listeria monocytogenes and Salmonella Enteritidis were studied using polystyrene as the model surface. The pre-conditioning with surfactin 0.25% reduced by 42.0% the adhesion of L monocytogenes and S. Enteritidis, whereas the treatment using rhamnolipids 1.0% reduced by 57.8% adhesion of L monocytogenes and by 67.8% adhesion of S. aureus to polystyrene.Biosurfactants were less effective to avoid adhesion of mixed cultures of the bacteria when compared with individual cultures. After 2 h contact with surfactin at 0.1% concentration, the pre-formed biofilms of S. aureus were reduced by 63.7%, L. monocytogenesby 95.9%, S. Enteritidis by 35.5% and the mixed culture biofilm by 58.5%. The rhamnolipids at 0.25% concentration removed 58.5% the biofilm of S. aureus, 26.5% of L monocytogenes, 23.0% of S. Enteritidis and 24.0% the mixed culture after 2 h contact. In general, the increase in concentration of biosurfactants and in the time of contact decreased biofilm removal percentage. These results suggest that surfactin and rhamnolipids can be explored to control the attachment and to disrupt biofilms of individual and mixed cultures of the food-borne pathogens. (C) 2011 Elsevier Ltd. All rights reserved.

In situ Evaluation of the Erosive Potential of Orange Juice Modified by Food Additives

The aim of this study was to evaluate the erosive potential of orange juice modified with food-approved additives: 0.4 g/l of calcium (Ca) from calcium lactate pentahydrate, 0.2 g/l of linear sodium polyphosphate (LPP) or their combination (Ca+LPP) were added to a commercially available orange juice (negative control, C-). A commercially available calcium-modified orange juice (1.6 g/l of calcium) was the positive control (C+). These juices were tested using a short-term erosion in situ model, consisting of a five-phase, single-blind crossover clinical trial involving 10 subjects. In each phase, subjects inserted custom-made palatal appliances containing 8 bovine enamel specimens in the mouth and performed erosive challenges for a total of 0 (control), 10, 20, and 30 min. Two specimens were randomly removed from the appliances after each challenge period. Enamel surface microhardness was measured before and after the clinical phase and the percentage of surface microhardness change (%SMC) was determined. Before the procedures, in each phase, the subjects performed a taste test, where the juice assigned to that phase was blindly compared to C-. Overall, C+ showed the lowest %SMC, being the least erosive solution (p < 0.05), followed by Ca+LPP and Ca, which did not differ from each other (p > 0.05). LPP and C- were the most erosive solutions (p <0.05). Taste differences were higher for C+ (5/10 subjects) and Ca (4/10 subjects), but detectable in all groups, including C- (2/10 subjects). Calcium reduced the erosive potential of the orange juice, while no protection was observed for LPP. Copyright (C) 2012 S. Karger AG, Basel

Qualifying instrument for evaluation of food and nutritional care in hospital

Establishing criteria for hospital nutrition care ensures that quality care is delivered to patients. The responsibility of the Hospital Food and Nutrition Service (HFNS) is not always well defined, despite efforts to establish guidelines for patient clinical nutrition practice. This study describes the elaboration of an Instrument for Evaluation of Food and Nutritional Care (IEFNC) aimed at directing the actions of the Hospital Food and Nutrition Service. This instrument was qualified by means of a comparative analysis of the categories related to hospital food and nutritional care, published in the literature. Elaboration of the IEFNC comprised the following stages: (a) a survey of databases and documents for selection of the categories to be used in nutrition care evaluation, (b) a study of the institutional procedures for nutrition practice at two Brazilian hospitals, in order to provide a description of the sequence of actions that should be taken by the HFNS as well as other services participating in nutrition care, (c) design of the IEFNC based on the categories published in the literature, adapted to the sequence of actions observed in the routines of the hospitals under study, (d) application of the questionnaire at two different hospitals that was mentioned in the item (b), in order to assess the time spent on its application, the difficulties in phrasing the questions, and the coverage of the instrument, and (e) finalization of the instrument. The IEFNC consists of 50 open and closed questions on two areas of food and nutritional care in hospital: inpatient nutritional care and food service quality. It deals with the characterization and structure of hospitals and their HFNS, the actions concerning the patients' nutritional evaluation and monitoring, the meal production system, and the hospital diets. "This questionnaire is a tool that can be seen as a portrait of the structure and characteristics of the HFNS and its performance in clinical and meal management dietitian activities." (Nutr Hosp. 2012;27:1170-1177) DOI:10.3305/nh.2012.27.4.5868

Food safety in wine: optimization of analytical controls and evaluation of production technologies

This PhD thesis has been proposed to validate and then apply innovative analytical methodologies for the determination of compounds with harmful impact on human health, such as biogenic amines and ochratoxin A in wines. Therefore, the influence of production technology (pH, amino acids precursor and use of different malolactic starters) on biogenic amines content in wines was evaluated. An HPLC method for simultaneous determination of amino acids and amines with precolumnderivatization with 9-Fluorenyl-methoxycarbonyl chloride (FMOC-Cl) and UV detection was developed. Initially, the influence of pH, time of derivatization, gradient profile were studied. In order to improve the separation of amino acids and amines and reduce the time of analysis, it was decided to study the influence of different flows and the use of different columns in the chromatographic method. Firstly, a C18 Luna column was used and later two monolithic columns Chromolith in series. It appeared to be suitable for an easy, precise and accurate determination of a relatively large number of amino acids and amines in wines. This method was then applied on different wines produced in the Emilia Romagna region. The investigation permitted to discriminate between red and white wines. Amino acids content is related to the winemaking process. Biogenic amines content in these wines does not represent a possible toxicological problem for human health. The results of the study of influence of technologies and wine composition demonstrated that pH of wines and amino acids content are the most important factors. Particularly wines with pH > 3,5 show higher concentration of biogenic amines than wines with lower pH. The enrichment of wines by nutrients also influences the content of some biogenic amines that are higher in wines added with amino acids precursors. In this study, amino acids and biogenic amines are not statistically affected by strain of lactic acid bacteria inoculated as a starter for malolactic fermentation. An evaluation of different clean-up (SPE-MycoSep; IACs and LLE) and determination methods (HPLC and ELISA) of ochratoxin A was carried out. The results obtained proved that the SPE clean-up are reliable at the same level while the LLE procedures shows lowest recovery. The ELISA method gave a lower determination and a low reproducibility than HPLC method.

Determination of bioactive and potentially toxic compounds in food: raw material analysis and shelf life evaluation

"Bioactive compounds" are extranutritional constituents that typically occur in small quantities in food. They are being intensively studied to evaluate their effects on health. Bioactive compounds include both water soluble compounds, such as phenolics, and lipidic substances such as n-3 fatty acids, tocopherols and sterols. Phenolic compounds, tocopherols and sterols are present in all plants and have been studied extensively in cereals, nuts and oil. n-3 fatty acids are present in fish and all around the vegetable kingdom. The aim of the present work was the determination of bioactive and potentially toxic compounds in cereal based foods and nuts. The first section of this study was focused on the determination of bioactive compounds in cereals. Because of that the different forms of phytosterols were investigated in hexaploid and tetraploid wheats. Hexaploid cultivars were the best source of esterified sterols (40.7% and 37.3% of total sterols for Triticum aestivum and Triticum spelta, respectively). Significant amounts of free sterols (65.5% and 60.7% of total sterols for Triticum durum and Triticum dicoccon, respectively) were found in the tetraploid cultivars. Then, free and bound phenolic compounds were identified in barley flours. HPLCESI/ MSD analysis in negative and positive ion mode established that barley free flavan-3- ols and proanthocyanidins were four dimers and four trimers having (epi)catechin and/or (epi)gallocatechin (C and/or GC) subunits. Hydroxycinnamic acids and their derivatives were the main bound phenols in barley flours. The results obtained demonstrated that barley flours were rich in phenolic compounds that showed high antioxidant activity. The study also examined the relationships between phenolic compounds and lipid oxidation of bakery. To this purpose, the investigated barley flours were used in the bakery production. The formulated oven products presented an interesting content of phenolic compounds, but they were not able to contain the lipid oxidation. Furthermore, the influence of conventional packaging on lipid oxidation of pasta was evaluated in n-3 enriched spaghetti and egg spaghetti. The results proved that conventional packaging was not appropriated to preserve pasta from lipid oxidation; in fact, pasta that was exposed to light showed a high content of potentially toxic compounds derived from lipid oxidation (such as peroxide, oxidized fatty acids and COPs). In the second section, the content of sterols, phenolic compounds, n-3 fatty acids and tocopherols in walnuts were reported. Rapid analytical techniques were used to analyze the lipid fraction and to characterize phenolic compounds in walnuts. Total lipid chromatogram was used for the simultaneous determination of the profile of sterols and tocopherols. Linoleic and linolenic acids were the most representative n-6 and n-3 essential dietary fatty acids present in these nuts. Walnuts contained substantial amounts of γ- and δ-tocopherol, which explained their antioxidant properties. Sitosterol, Δ5-avenasterol and campesterol were the major free sterols found. Capillary electrophoresis coupled to DAD and microTOF was utilized to determine phenolic content of walnut. A new compound in walnut ((2E,4E)- 8-hydroxy-2,7-dimethyl-2,4-decadiene-1,10-dioic acid 6-O-β-D-glucopiranosyl ester, [M−H]− 403.161m/z) with a structure similar to glansreginins was also identified. Phenolic compounds corresponded to 14–28% of total polar compounds quantified. Aglycone and glycosylated ellagic acid represented the principal components and account for 64–75% of total phenols in walnuts. However, the sum of glansreginins A, B and ((2E,4E)-8-hydroxy- 2,7-dimethyl-2,4-decadiene-1,10-dioic acid 6-O-β-D-glucopiranosyl ester was in the range of 72–86% of total quantified compounds.

Development of instrumental and sensory analytical methods of food obtained by traditional and emerging technologies

The consumer demand for natural, minimally processed, fresh like and functional food has lead to an increasing interest in emerging technologies. The aim of this PhD project was to study three innovative food processing technologies currently used in the food sector. Ultrasound-assisted freezing, vacuum impregnation and pulsed electric field have been investigated through laboratory scale systems and semi-industrial pilot plants. Furthermore, analytical and sensory techniques have been developed to evaluate the quality of food and vegetable matrix obtained by traditional and emerging processes. Ultrasound was found to be a valuable technique to improve the freezing process of potatoes, anticipating the beginning of the nucleation process, mainly when applied during the supercooling phase. A study of the effects of pulsed electric fields on phenol and enzymatic profile of melon juice has been realized and the statistical treatment of data was carried out through a response surface method. Next, flavour enrichment of apple sticks has been realized applying different techniques, as atmospheric, vacuum, ultrasound technologies and their combinations. The second section of the thesis deals with the development of analytical methods for the discrimination and quantification of phenol compounds in vegetable matrix, as chestnut bark extracts and olive mill waste water. The management of waste disposal in mill sector has been approached with the aim of reducing the amount of waste, and at the same time recovering valuable by-products, to be used in different industrial sectors. Finally, the sensory analysis of boiled potatoes has been carried out through the development of a quantitative descriptive procedure for the study of Italian and Mexican potato varieties. An update on flavour development in fresh and cooked potatoes has been realized and a sensory glossary, including general and specific definitions related to organic products, used in the European project Ecropolis, has been drafted.

Fish quality assessment through the application of chemico-physical, sensory and microbiological analyses

The quality of fish products is indispensably linked to the freshness of the raw material modulated by appropriate manipulation and storage conditions, specially the storage temperature after catch. The purpose of the research presented in this thesis, which was largely conducted in the context of a research project funded by Italian Ministry of Agricultural, Food and Forestry Policies (MIPAAF), concerned the evaluation of the freshness of farmed and wild fish species, in relation to different storage conditions, under ice (0°C) or at refrigeration temperature (4°C). Several specimens of different species, bogue (Boops boops), red mullet (Mullus barbatus), sea bream (Sparus aurata) and sea bass (Dicentrarchus labrax), during storage, under the different temperature conditions adopted, have been examined. The assessed control parameters were physical (texture, through the use of a dynamometer; visual quality using a computer vision system (CVS)), chemical (through footprint metabolomics 1H-NMR) and sensory (Quality Index Method (QIM). Microbiological determinations were also carried out on the species of hake (Merluccius merluccius). In general obtained results confirmed that the temperature of manipulation/conservation is a key factor in maintaining fish freshness. NMR spectroscopy showed to be able to quantify and evaluate the kinetics for unselected compounds during fish degradation, even a posteriori. This can be suitable for the development of new parameters related to quality and freshness. The development of physical methods, particularly the image analysis performed by computer vision system (CVS), for the evaluation of fish degradation, is very promising. Among CVS parameters, skin colour, presence and distribution of gill mucus, and eye shape modification evidenced a high sensibility for the estimation of fish quality loss, as a function of the adopted storage conditions. Particularly the eye concavity index detected on fish eye showed a high positive correlation with total QIM score.

Physico-chemical and microstructural properties of food dispersions

The macroscopic properties of oily food dispersions, such as rheology, mechanical strength, sensory attributes (e.g. mouth feel, texture and even flavour release) and as well as engineering properties are strongly determined by their microstructure, that is considered a key parameter in the understanding of the foods behaviour . In particular the rheological properties of these matrices are largely influenced by their processing techniques, particle size distribution and composition of ingredients. During chocolate manufacturing, mixtures of sugar, cocoa and fat are heated, cooled, pressurized and refined. These steps not only affect particle size reduction, but also break agglomerates and distribute lipid and lecithin-coated particles through the continuous phase, this considerably modify the microstructure of final chocolate. The interactions between the suspended particles and the continuous phase provide information about the existing network and consequently can be associated to the properties and characteristics of the final dispersions. Moreover since the macroscopic properties of food materials, are strongly determined by their microstructure, the evaluation and study of the microstructural characteristics, can be very important for a through understanding of the food matrices characteristics and to get detailed information on their complexity. The aim of this study was investigate the influence of formulation and each process step on the microstructural properties of: chocolate type model systems, dark milk and white chocolate types, and cocoa creams. At the same time the relationships between microstructural changes and the resulting physico-chemical properties of: chocolate type dispersions model systems dark milk and white chocolate were investigated.

Evaluation of colonoscopic allergen provocation as a diagnostic tool in dogs with proven food hypersensitivity reactions

OBJECTIVE: To evaluate the colonoscopic allergen provocation (COLAP) test as a new tool for the diagnosis of IgE-mediated food allergy. METHODS: Oral food challenges as well as COLAP testing were performed in a colony of nine research dogs with proven immediate-type food allergic reactions. In addition, COLAP was performed in five healthy dogs. RESULTS: When compared with the oral challenge test, COLAP accurately determined 18 of 23 (73 per cent) positive oral challenge reactions (73 per cent) in dogs with food allergies and was negative in the healthy dogs. CLINICAL SIGNIFICANCE: The accuracy of this new test may be higher than that for gastric sensitivity testing. Therefore, COLAP holds promise as a new test to confirm the diagnosis of suspect IgE-mediated food allergy in dogs.

The use of an electronic von Frey device for evaluation of sensory threshold in neurologically normal dogs and those with acute spinal cord injury

The utility and inter-session repeatability of sensory threshold measurements using an electronic von Frey anesthesiometer (VFA) were assessed in a group of six neurologically normal dogs. Sensory threshold values obtained in neurologically normal dogs were compared to those of dogs with acute spinal cord injury (SCI) caused by intervertebral disc extrusion (n=6) and to a group of neurologically normal dogs with cranial cruciate ligament rupture (CCLR; n=6). Sensory threshold values in neurologically normal dogs were 155.8 ± 37.7 g and 154.7 ± 67.2 g for the left and right pelvic limbs, respectively. The difference in mean sensory threshold values obtained for the group when two distinct testing sessions were compared was not statistically significant (P>0.05). Mean sensory threshold values for the group with SCI were significantly higher than those for neurologically normal dogs at 351.1 ± 116.5 g and 420.3 ± 157.7 g for the left and right pelvic limbs, respectively (P=0.01). A comparison of sensory threshold values for the group with CCLR and neurologically normal dogs was not statistically significant (P>0.05). The modified dorsal technique for VFA described here represents a reliable method to assess sensory threshold in neurologically normal dogs and in those with SCI.

Experimental evaluation of seaweeds as a vector for microplastics into marine food webs, supplementary material

The ingestion of microplastics has been shown for a great variety of marine organisms. However, benthic marine mesoherbivores such as the common periwinkle Littorina littorea have been largely disregarded in studies about the effects of microplastics on the marine biota, probably because the pathway for microplastics to this functional group of organisms was not obvious. In laboratory experiments we showed that the seaweed Fucus vesiculosus retains suspended microplastics on its surface. The numbers of microplastics that adhered to the algae correlated with the concentrations of suspended particles in the water. In choice feeding assays L. littorea did not distinguish between algae with adherent microplastics and clean algae without microplastics, indicating that the snails do not recognize solid nonfood particles in the submillimeter size range as deleterious. In periwinkles that were feeding on contaminated algae, microplastics were found in the stomach and in the gut. However, no microplastics were found in the midgut gland, which is the principle digestive organ of gastropods. Microplastics in the fecal pellets of the periwinkles indicate that the particles do not accumulate rapidly inside the animals but are mostly released with the feces. Our results provide the first evidence that seaweeds may represent an efficient pathway for microplastics from the water to marine benthic herbivores.

Woolliness assessment in peaches (Cv. Springcrest) by sensory and instrumental means.

Mealiness is a negative attribute of sensory texture, characterised by the lack of juiciness without variation of total water content in the tissues. In peaches, mealiness is also known as "woolliness" and "leatheriness". This internal disorder is characterised by the lack of juiciness and flavour. In peaches, it is associated with interna browning near the stone and the incapacity of ripening although there is externa ripe appearance. Woolliness is associated with inadequate cold storage and is considered as a physiological disorder that appears in stone fruits when an unbalanced pectolitic enzyme activity during storage occurs (Kailasapathy and Melton, 1992). Many attempts have been carried out to identify and measure mealiness and woolliness in fruits. The texture of a food product is composed by a wide spectrum of sensory attributes. Consumer defines the texture integrating simultaneously all the sensory attributes. However, an instrument assesses one or several parameters related to a fraction of the texture spectrum (Kramer, 1973). The complexity of sensory analysis by means of trained panels to assess the quality of some producing processes, supports the attempt to estimate texture characteristics by instrumental means. Some studies have been carried out comparing sensory and instrumental methods to assess mealiness and woolliness. The current study is centered on analysis and evaluation of woolliness in peaches and is part of the European project FAIR CT95 0302 "Mealiness in fruits: consumer perception and means for detection". The main objective of this study was to develop procedures to detect woolly peaches by sensory and by instrumental means, as well as to compare both measuring procedures.