Influence of baking conditions and formulation on furanic derivatives, 3-methylbutanal and hexanal and other quality characteristics of lab-made and commercial biscuits

Biscuit baking can cause the formation of heat-related toxic compounds, mainly through the Maillard reaction, including some volatile organic compounds (VOCs) that are potentially carcinogenic to humans. This study investigates the effects of different baking conditions and recipes on quality characteristics (moisture, water activity, colour, texture) and on the concentration of some VOCs (furfural, furfuryl acetate, 5-methylfurfural, furfuryl alcohol, 3-methylbutanal, hexanal) in biscuits. Specifically, lab-made biscuits baked under static and ventilated conditions and three commercial biscuit types categorised as shortbreads with eggs, with chocolate chips and dry petits were evaluated. Concerning the lab-made biscuits, the ventilated mode resulted in faster baking and a slightly lower concentration of investigated VOCs compared to the static mode. Besides the process conditions, the recipe also played a role in the final quality and target volatiles, whose concentrations were lower in dry petits than in shortbreads, which are characterised by higher sugar and fat contents.

Characterization and evaluation of the influence of an alginate, cocoa and a bilayer alginate-cocoa coating on the quality of fresh-cut oranges during storage

BACKGROUND

Fresh-cut products are ready-to-use goods which retain the fresh characteristics of raw produce. However, numerous factors restrict the quality and shelf-life of fresh-cut products. One of the most promising, convenient and safe technologies to preserve the quality and to prolong the shelf-life of fresh fruits and vegetables is the application of edible coatings.

RESULTS

The aim of this study was to investigate the effects of different coatings (alginate-based, cocoa-based and a combination of them) on physicochemical, microbiological and sensory characteristics of fresh-cut oranges during storage. Preliminary rheological analyses were performed on coatings in order to characterize them. The three different coated orange samples were packaged in polyethylene terephthalate trays under atmospheric conditions and stored for 9 days at 6 °C. During storage, all samples were analysed for water activity, moisture, colour, texture, microbiological analyses and sensory quality. Orange samples coated with sodium alginate maintained the highest quality characteristics in terms of texture and microbiological properties, but not from a sensory point of view. Samples coated only with cocoa presented very high sensory attributes, but the lowest microbiological and textural quality. Samples covered in both alginate and cocoa demonstrated the best quality parameters throughout the whole storage period, including high sensory characteristics and the lowest microbiological cell loads (yeast and mesophilic aerobic bacteria under the threshold limit of 6.0 log cfu g^-1 ).

CONCLUSION

The bilayer coating represented the best solution in order to develop new ready to-eat-fresh oranges with both high textural and sensory attributes and prolonged shelf-life. © 2022 Society of Chemical Industry.

P295 EXERCISE OXYGEN KINETIC IN HYPERTROPHIC CARDIOMYOPATHY: RESULTS FROM A MULTICENTER CARDIOPULMONARY EXERCISE TESTING STUDY

Aims

Reduced cardiac output (CO) has been considered crucial in symptoms’ genesis in hypertrophic cardiomyopathy (HCM). We evaluated the cardiopulmonary exercise testing (CPET) response in HCM focusing on parameters strongly associated with stroke volume (SV) and cardiac output (CO), such as oxygen uptake (VO2) and O2–pulse, considering both their absolute values and temporal behavior during physical exercise.

Methods and Results

We enrolled 312 non–end stage HCM patients, divided according to left ventricle outflow tract obstruction (LVOTO) at rest or during Valsalva maneuver (72% with LVOTO<30; 10% between 30 and 49 and 18% ≥ 50mmHg). Peak VO2 (percent of predicted), O2–pulse and ventilation to carbon dioxide production (VE/VCO2) slope did not change across LVOTO groups. Ninety–six (31%) HCM patients presented an abnormal O2–pulse temporal behavior, irrespective of LVOTO values. These patients showed lower peak systolic pressure, workload (106±45 vs. 130±49W), VO2 (74±17 vs. 80±20%) and O2–pulse (12 [9–14] vs. 14 [11–17]ml/beat), with higher VE/VCO2 slope (28 [25–31] vs. 27 [24–31]) (p < 0.005 for all). Only 2 patients had an abnormal VO2/work slope.

Conclusion

None of CPET parameters, either as absolute values or dynamic relationships, were associated with LVOTO. Differently, an abnormal O2–pulse exercise behavior, which is strongly related to inadequate SV during exercise, correlates with reduced functional capacity (peak and anaerobic threshold VO2 and workload) and increased VE/VCO2 slope, helping identifying more advanced disease irrespectively of LVOTO. Adding O2–pulse kinetics evaluation to standard CPET could lead to a potential incremental benefit in terms of HCM prognostic stratification and, then, therapeutic management.

Modifications to mobile chest radiography technique during the COVID-19 pandemic - implications of X-raying through side room windows

INTRODUCTION

Modifications to common radiographic techniques have resulted from the challenges presented by the COVID-19 pandemic. Reports exist regarding the potential benefits of undertaking mobile radiography through side room windows. The aim of this study was to evaluate the impact on image quality and exposure factors when undertaking such examinations.

METHODS

A phantom based study was undertaken using a digital X-ray room. Control acquisitions, using a commercially available image quality test tool, were performed using standard mobile chest radiography acquisition factors. Image quality (physical and visual), incidence surface air kerma (ISAK), Exposure Index (EI) and Deviation Index (DI) were recorded. Image quality and radiation dose were further assessed for two additional (experimental) scenarios, where a side room window was located immediately adjacent to the exit port of the light beam diaphragm. The goal of experimental scenario one was to modify exposure factors to maintain the control ISAK. The goal of experimental scenario two was to modify exposure factors to maintain the control EI and DI. Dose and image quality data were compared between the three scenarios.

RESULTS

To maintain the pre-window (control) ISAK (76 μGy), tube output needed a three-fold increase (90 kV/4 mAs versus 90 kV/11.25 mAs). To maintain EI/DI a more modest increase in tube output was required (90 kV/8 mAs/ISAK 54 μGy). Physical and visual assessments of spatial resolution and signal-to-noise ratio were indifferent between the three scenarios. There was a slight statistically significant reduction in contrast-to-noise ratio when imaging through the glass window (2.3 versus 1.4 and 1.2; P = 0.005).

CONCLUSION

Undertaking mobile X-ray examinations through side room windows is potentially feasible but does require an increase in tube output and is likely to be limited by minor reductions in image quality.

IMPLICATIONS FOR PRACTICE

Mobile examinations performed through side room windows should only be used in limited circumstances and future clinical evaluation of this technique is warranted.

Influence of different baking powders on physico-chemical, sensory and volatile compounds in biscuits and their impact on textural modifications during soaking

The aim of this study was to investigate the effects of different type of leavening agents (ammonium bicarbonate-A, cream of tartar-B, grape-based leavening agent-C, baking powder-D) on the structural (also after soaking), physico-chemical and other quality characteristics of biscuits made with the same formulation. The major changes observed between samples were related to their textural properties, volatile profile and sensory characteristics. The presence of ammonium bicarbonate in sample A, gave arise to a biscuit with the most homogeneous surface appearance, the less hard structure and highest fracturability and spread, that promoted their greater milk uptake during soaking. The B and C biscuits, made with baking powder having tartaric acid, were characterized by a crisper texture and lower sensory overall acceptability. The presence in formulation of baking powders made with cream of tartar (B) and ammonium bicarbonate (A) mostly influenced the biscuit volatile profiles. Biscuit sample obtained with the most common baking powder (diphosphates powder) showed in general intermediate characteristics between A and B-C samples. Results obtained in this study demonstrate that a lot of final properties of biscuits can be strongly influenced by the type of leavening agents used in formulation.

Acrylamide in coffee: formation and possible mitigation strategies - a review

It is widely known that acrylamide, present in some different heat-treated foods, is an important toxic compound to humans. Coffee beverage is one of the most important sources of acrylamide, because the raw bean contains the reaction substrates and it is processed at very high temperature during roasting. Due to its high consumption all over the world, it is necessary to find applicable solutions to decrease the concentration of this undesired Maillard reaction product.The present review summarizes the advance made in understanding the acrylamide formation and describes the potential acrylamide reduction strategies along all coffee production steps, from raw material to coffee brew preparation with a dominant focus on roasting stage.Currently, it is quite established that the selection of the highest quality Arabica green coffee variety, high roasting thermal input and shortest brewing techniques lead to low final acrylamide levels. There are also few innovative interventions proposed for acrylamide control in coffee such as enzymatic treatments of raw material, vacuum or steam roasting, roasted beans supercritical fluid extraction, final beverage treatments like yeast fermentation and amino acids/additive additions. However, for these strategies the impact on the desired sensorial and nutritional coffee brew properties must be evaluated and some proposed procedures are still difficult to be applied at real industrial scale. Furthermore, in-depth studies are needed in order to find appropriate and practical solutions for acrylamide mitigation in coffee with a holistic risk/benefit approach.

Glass transition of green and roasted coffee investigated by calorimetric and dielectric techniques

Solid and liquid components coexist into glassy and amorphous structures of food complex matrixes. Both states admit movements, promoting physical modifications to a more thermodynamically stable system. Green and roasted coffee beans are principally characterized by a glassy structure that slowly evolves during storage. The aim of this study was to assess calorimetric and dielectric properties in combination, as a useful multi-analytical technique to improve the understanding of the motion mechanism of localized molecules. After equilibration at different water activities (a_w) for the determination of sorption isotherms of green and roasted coffee, the glass transition temperature (Tg) of the samples has been measured by using differential scanning calorimetry (DSC). Increasing the a_w from 0.155 to 0.512, the Tg shifted from 48.76 (±0.04) to 34.89 (±0.02) °C for green coffee and from 45.73 (±0.05) to 40.15 (±0.10) °C for the roasted one. The spectroscopic fingerprint of the matrix has been determined by dielectric measurements in terms of "gain" spectra (related to the imaginary part of permittivity). The maximum values of the determination coefficient (R²), obtained by linear correlation between spectral data and water activity or glass transition values for a specific frequency of the whole range (1.6 GHz-2.7 GHz), were 0.999 and 0.943 for green, and 0.997 R² and 0.925 R² for roasted coffee respectively.

Essential rosemary oil enrichment of minimally processed potatoes by vacuum-impregnation

Vacuum impregnation (VI) has been recognized as a promising tool for the introduction of solutes into the internal structure of some porous food products. The enrichment of minimally processed potatoes with aromatic compounds could represent an interesting method for product innovation. This study was aimed at applying VI with rosemary essential oil on a minimally processed potato product in order to obtain an innovative fresh-cut potato product, and to evaluate its influence on the physico-chemical, sensorial and microbiological properties of potato sticks during refrigerated storage and after frying. A pressure of 60 mbar was applied for 30 min followed by a relaxation time at atmospheric pressure of 30 min to potato sticks immersed in rosemary oil solutions in concentration between 0 and 12%. Prepared samples were packed and stored at 4 °C for 14 days. Analytical determinations were carried out on the fresh and fried product. The weight gain of potatoes promoted by VI was in the range of 6-14%, depending on the concentration of rosemary essential oil. The rosemary essential oil concentration gradients of impregnated potato sticks were detected by GC analysis and sensorial test, evidencing their persistency during storage and after frying. The treatment seemed to improve microbiological stability, not affecting the texture, moisture, but slightly deteriorating the product color. Results obtained in the present study confirm the potentiality of VI for fresh products innovation.

Chemical and physical changes during storage of differently packed biscuits formulated with sunflower oil

Various innovative materials are already present on the market, but there is scarce knowledge on their performances when used in real food system. In this study, two innovative packaging materials were investigated for the evaluation during storage of biscuits formulated with sunflower oil and compared to a traditional one. To this aim, three different flexible and composite film containing a metalized plastic layer and a paper layer were used. The control included orientated polypropylene (OPP), while the innovative materials contained poly-lactic acid or OPP with a pro-oxidant additive, ethylene vinyl acetate. The physical (moisture, water activity, hardness/crispness) and chemical (peroxide value, conjugated dienes and trienes, and hexanal and nonanal formation) changes of biscuits were monitored during accelerated storage (35 °C and 50% of relative humidity for 105 days). Packaging materials did not have significant impact on textural quality of biscuits. Instead remarkable differences were observed during storage in the evolution of different lipid oxidation compounds, moisture content and water activity among differently packed biscuits. A new ecofriendly packaging showed the best performances in terms of physico-chemical quality of biscuits. The obtained results provide useful information for industrial application.

(Ultra) High Pressure Homogenization Potential on the Shelf-Life and Functionality of Kiwifruit Juice

The increasing competition within the food industry sector makes the requisite of innovation in processes and products essential, leading to focus the interest on the application of new processing technologies including high pressure homogenization (HPH) and ultra high pressure homogenization (UHPH). In this context, the present research aimed at evaluating the effects of two UHPH treatments performed at 200 MPa for 2 and 3 cycles on quality and functionality of organic kiwifruit juice stored at three different temperatures, i.e., 5, 15, and 25°C. The results showed that only the treatment performed at 200 MPa for 3 cycles was able to significantly increase the shelf-life of organic kiwifruit juices when stored at refrigeration temperature, avoiding also phase separation that occurred in the sample treated at 0.1 MPa (control) after 20 days of refrigerated storage. The obtained data showed also that the highest applied pressure was able to increase some quality parameters of the juice such as viscosity and luminosity (L^∗) and increased the availability of total phenol content consequently enhancing the juice total antioxidant activity. The application of a treatment at 200 MPa for 3 cycles allowed to obtain a stable kiwifruit juice for more than 40 days under refrigerated storage. A challenge to implement this technology in food process as full alternative to thermal treatment could be represented by the adoption of pressure level up to 400 MPa followed by the packaging in aseptic conditions.

Characterization of Active Edible Films based on Citral Essential Oil, Alginate and Pectin

Thermal, structural and physico-chemical properties of different composite edible films based on alginate and pectin with the addition of citral essential oil (citral EO) as an agent to improve barrier properties, were investigated. The obtained films were clear and transparent, with a yellow hue that increased with citral EO addition. All the films displayed good thermal stability up to 160 °C, with a slight improvement observed by increasing the amount of citral EO in the composites. Gas transmission rate (GTR) strongly depended on the polymer structure, gas type and temperature, with improvement in barrier performance for composite samples. Also, citral EO did not exert any weakening action on the tensile behavior. On the contrary, an increase of the elastic modulus and of the tensile strength was observed. Lastly, water contact angle measurements demonstrated the dependence of the film wettability on the content of citral EO.

Influence of the addition of soy product and wheat fiber on rheological, textural, and other quality characteristics of pizza

The effect of partial replacement of wheat flour with soy paste and wheat fiber on rheological, textural, physicochemical, and organoleptic characteristics of an enriched pizza base (E) was investigated in comparison with those of a control pizza base (C). New ingredients (e.g., enriched cooked ham, whey cheese, and tomato sauce realized using food industry by-products) were also used in E pizza topping to further increase its nutritional properties. Enriched dough was developed first at a laboratory level. Large and small deformation, moisture, leavening activity, and metabolic heat were tested. On the final product, produced at the industrial level, textural, color, sensory, and nutritional analyses were performed. Preliminary rheological analysis was essential to evaluate the suitability of the new pizza to be processed at industrial level. Both pizza dough samples showed a solid elastic-like behavior; however, the addition of soy and fiber increased moisture content of E pizza, due to the water binding ability of soy protein and to the effect of fibers that also decreased E dough elasticity. No differences in extensibility between the two samples were observed, whereas significantly lower values of resistance to extension and dough force were shown in sample E. These differences were likely due to the presence of soy that interfere with gluten formation and to the dietary fibers that interact with water. Ingredients used in E pizza improved its nutritional quality increasing dietary fibers and protein, and decreasing saturated fatty acids and cholesterol content, which contributed to decrease energy value, in terms of kilocalorie reduction.

PRACTICAL APPLICATIONS

In this work, the effects of using new ingredients (e.g., soy paste, wheat fiber) on the rheological, textural, physicochemical, nutritional, and organoleptic characteristics of an enriched pizza type were investigated both at laboratory and industrial levels. The new pizza provides a product that combines solid technological performances, in terms of rheological properties and dough elasticity, with improved and balanced nutritional quality, thanks also to the ingredients used in the topping. Results demonstrate the possibility of obtaining new pizza products characterized by nutritional and sensorial properties tailored for different group of consumers.

Differential expression of innate immune response genes in clinical phases of chronic hepatitis B infection

We investigated innate immune gene expression in clinical phases of chronic hepatitis B infection, including immune tolerant (IT), immune active (IA), inactive carrier (IC) and hepatitis B e antigen (HBeAg)-negative phases, as well as healthy controls. Expression levels of interferon types I, II and III, their receptor subunits, IRFs, TLRs and other IFN-induced genes in peripheral blood mononuclear cells were compared. Forty HBsAg-positive treatment-naïve subjects without co-infection with HIV, HCV or HDV were enrolled. To complement the viral load, the expression levels of 37 innate immune genes were measured by qPCR. The highest response of the innate immune system was observed in the IT and HBeAg-negative phases, and the IC phase had the lowest response; 31 of the 37 studied genes reached their maximum mRNA expression levels in the IT and HBeAg-negative phases, and the minimum expression levels of 23 genes were found in the IC phase. The highest mRNA expression levels of IFNs, IFN receptor subunits, IRFs and TLRs genes in all clinical phases were IFN-λ2 and 3, IFN-γR2, IRF7 and TLR7, and the lowest levels of mRNA expression were observed for IFN-α, IFN-λR1, IRF8 and TLR2. We conclude that innate immune response genes are expressed differentially among chronic HBV phases, and this difference may help to develop new precise and noninvasive methods to determine the progression of disease in chronic HBV patients.

Chronic obstructive pulmonary disease (COPD) exacerbation: impact of comorbidities on length and costs during hospitalization

OBJECTIVE

A retrospective cohort study was performed, using administrative database of the Local Health Unit Roma-A (LHU RM-A). The included subjects were residing in one of the four districts and were hospitalized for COPD exacerbation in healthcare facilities of the LHU during years 2010-2012.

PATIENTS AND METHODS

The aim of the present study is to evaluate the impact of comorbidities, length and costs of hospital stay in patients with COPD exacerbations. Chronic obstructive pulmonary disease (COPD) is often associated with other diseases (cardiovascular diseases, diabetes, metabolic syndrome, chronic renal failure, depression) that can increase risk of mortality and hospitalization.

RESULTS

A total of 1890 COPD patients are included in the study. The mean length of hospitalization is 12.25 days (SD ± 10.91), 11.63 days (SD ± 9.76) and 11.91 days (SD ± 9.69) with a mean cost of hospitalization amounting to euro 3683.48 (SD ± 2037.12), 3356.82 (SD ± 1674.86) and 3706.81 (SD ± 2087.72) in 2010, 2011 and 2012 respectively. The presence and number of comorbidities are positively and significantly associated to the length and cost of hospitalization. In particular, patients with cardiovascular diseases or diabetes mellitus associated with other comorbidities present the highest values of hospital stay and cost. The cost and the length of hospitalization were significantly linked to the number of comorbidities.

CONCLUSIONS

Comorbidities play an important role in the hospital management of COPD exacerbation, increasing health care costs related to this disease.

Moisture adsorption behaviour of biscuit during storage investigated by using a new Dynamic Dewpoint method

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.

Early use of non invasive ventilation in patients with amyotrophic lateral sclerosis: what benefits?

OBJECTIVE

The aim of this study was to analyze the efficacy of an early start of NIV in ALS patients, evaluating respiratory and ventilatory parameters.

PATIENTS AND METHODS

Functional respiratory parameters and arterial blood gas analysis were evaluated in forty-six patients. All patients were informed about the benefits and possible adverse effects of therapeutic support with NIV and divided in two groups based on the compliance to early start therapy with NIV (Group A) or not (Group B).

RESULTS

Among 46 ALS patients consecutively visited in our Unit, we included 20 patients in the Group A and 16 in the Group B. We have emphasized the importance of the early use of NIV stressing the difference between two groups analyzed, particularly in terms of pulmonary function tests and arterial blood gas analysis. Significant correlation was observed between Vital Capacity (VC), Forced Expiratory volume in one second (FEV1), and maximal inspiratory pressures (PImax).

CONCLUSIONS

Our study highlights the importance of noninvasive mechanical ventilation as a treatment for ALS patients and also shows the early start of NIV as an important approach in order to postpone the functional decline and the decrease of respiratory muscle strength.

Effect of Microwave Heating on Phytosterol Oxidation

The oxidative stability of phytosterols during microwave heating was evaluated. Two different model systems (a solid film made with a phytosterol mixture (PSF) and a liquid mixture of phytosterols and triolein (1:100, PS + TAG (triacylglycerol))) were heated for 1.5, 3, 6, 12, 20, and 30 min at 1000 W. PS degraded faster when they were microwaved alone than in the presence of TAG, following a first-order kinetic model. Up to 6 min, no phytosterol oxidation products (POPs) were generated in both systems. At 12 min of heating, the POP content reached a higher level in PSF (90.96 μg/mg of phytosterols) than in PS + TAG (22.66 μg/mg of phytosterols), but after 30 min of treatment, the opposite trend was observed. 7-Keto derivates were the most abundant POPs in both systems. The extent of phytosterol degradation depends on both the heating time and the surrounding medium, which can impact the quality and safety of the food product destined to microwave heating/cooking.

Effect of different new packaging materials on biscuit quality during accelerated storage

BACKGROUND

The effect of innovative multilayer packaging materials versus a standard one on biscuit quality was studied during accelerated storage at 25, 35, 45 °C and 50% relative humidity for 92 days. Three different packaging materials were used: metalized orientated polypropylene (OPP)/paper (control); metalized poly-lactic acid (PLA)/paper; metalized OPP with ethylene vinyl acetate pro-oxidant additive (EVA-POA)/paper. EVA-POA additive is used to make the plastic layer biodegradable. Various quality sample parameters (moisture, water activity (aw ), texture, peroxide value (PV), hexanal) were analysed during storage. Rate constants (k) and activation energies (Ea ) of hydration reactions and hexanal formation were calculated.

RESULTS

No remarkable differences in the evolution of primary and secondary lipid oxidation were observed among differently packed biscuits during storage. All samples maintained PV levels between 4 and 14 meq O2 kg(-1) oil. The product in flexible packaging with PLA reached the highest moisture and aw levels, but they did not significantly and adversely affect the other quality characteristics.

CONCLUSION

The obtained results demonstrate that the new tested packaging materials were suitable for commercial biscuit storage, having similar performance and preservation effects on the overall product quality to those of the standard one. Furthermore, these results could make a contribution to the food industry, encouraging the use of packaging materials with a negligible environmental impact as an alternative to petroleum-based ones.

Atrial fibrillation in the acute, hypercapnic exacerbations of COPD

OBJECTIVE

Chronic obstructive pulmonary disease (COPD) has been associated with a high frequency of arrhythmias. Atrial fibrillation (AF) is one of the most common arrhythmias and causes substantial morbidity and mortality. Emerging risk factors for the development of AF include a variety of breathing disorders like COPD. Few studies have analyzed the role of reduced lung function and respiratory acidosis in predicting AF. Aim of the current study was to investigate the role of hypercapnia, pulmonary systolic hypertension and lung function impairment in COPD patients, as risk factors for atrial fibrillation development.

PATIENTS ANDV METHODS

We evaluated a population of individuals consecutively hospitalized for COPD exacerbation and hypercapnic respiratory failure between January 2012 and January 2013; among them we selected a subgroup of patients presenting a paroxysmal episode of atrial fibrillation. All patients underwent pulmonary function tests, haemogasanalysis, electrocardiogram and transthoracic echocardiography.

RESULTS

Among the 193 subjects evaluated, 35 individuals with AF and COPD were enrolled in the study. Risk of new AF was higher in those subjects with lower FEV1 and higher PaCO2 values, also there was a significantly increased prevalence of AF in patients with higher value of Pulmonary Artery Systolic Pressure (PASP), obtained by transthoracic echocardiography. Linear correlation between variables revealed a direct relationships between hypercapnia and PASP and left and right atrial areas.

CONCLUSIONS

Impaired pulmonary function, hypercapnia and high values of PASP are independent predictors of incident AF.

The influence of different processing stages on particle size, microstructure, and appearance of dark chocolate

The effect of different process stages on microstructural and visual properties of dark chocolate was studied. Samples were obtained at each phase of the manufacture process: mixing, prerefining, refining, conching, and tempering. A laser light diffraction technique and environmental scanning electron microscopy (ESEM) were used to study the particle size distribution (PSD) and to analyze modifications in the network structure. Moreover, colorimetric analyses (L*, h°, and C*) were performed on all samples. Each stage influenced in stronger way the microstructural characteristic of products and above all the PSD. Sauter diameter (D [3.2]) decreased from 5.44 μm of mixed chocolate sample to 3.83 μm, of the refined one. ESEM analysis also revealed wide variations in the network structure of samples during the process, with an increase of the aggregation and contact point between particles from mixing to refining stage. Samples obtained from the conching and tempering were characterized by small PS, and a less dense aggregate structure. From color results, samples with the finest particles, having larger specific surface area and the smallest diameter, appeared lighter and more saturated than those with coarse particles.

PRACTICAL APPLICATION

Final quality of food dispersions is affected by network and particles characteristics. The deep knowledge of the influence of single processing stage on chocolate microstructural properties is useful in order to improve or modify final product characteristics. ESEM and laser diffraction are suitable techniques to study changes in chocolate microstructure.