Influence of lupin and chickpea flours on acrylamide formation and quality characteristics of biscuits.

Asparagine and sugars are direct precursors of acrylamide; however, proteins and fibres can also influence it. In this study, biscuits prepared replacing wheat flour with increasing concentrations (20, 40, 60%) of lupin or chickpea flour were investigated. Asparagine concentration was equalized in all formulas to isolate the effect of other flour characteristics on the acrylamide formation during baking. The results showed that replacing wheat flour with lupin flour increased acrylamide from 583.9 up to 1443 µg/kg after 9 min of baking, while 20-40% chickpea flour reduced acrylamide to 354.4-312.6 µg/kg. The acrylamide reduction using chickpea was attributed to the lower interaction between precursors resulting from both the coarser particle size and the lower reactivity of carbohydrate in presence of chickpea proteins. Chickpea addition did not affect the colour and texture of biscuits, opening the possibility for large-scale implementation of this mitigation strategy in formulas with a similar initial asparagine content.

Rheological and Viscoelastic Properties of Chitosan Solutions Prepared with Different Chitosan or Acetic Acid Concentrations.

Chitosan (Ch) is a partially crystalline biopolymer, insoluble in pure water but soluble in acid solutions. It has attracted interest from researchers to prepare solutions using different acid types and concentrations. This research aims to study both the effect of chitosan (Ch) or acetic acid (Ac) concentrations, at different temperatures, on rheological and viscoelastic properties of Ch solutions. To study the effect of Ch, solutions were prepared with 0.5−2.5 g Ch/100 g of solution and Ac = 1%, whereas to study the effect of Ac, the solutions were prepared with 2.0 g of Ch/100 g of solution and Ac = 0.2−1.0%. Overall, all analyzed solutions behaved as pseudoplastic fluid. The Ch strongly affected rheological properties, the consistency index (K) increased and the index flow behavior (n) decreased as a function of Ch. The activation energy, defined as the energy required for the molecule of a fluid to move freely, was low for Ch = 0.5%. The effect of Ac was less evident. Both K and n varied according to a positive and negative, respectively, parabolic model as a function of Ac. Moreover, all solutions, irrespective of Ch and Ac, behaved as diluted solutions, with G" > G'. The relaxation exponent (n") was always higher than 0.5, confirming that these systems behaved as a viscoelastic liquid. This n" increased with Ch, but it was insensitive to Ac, being slightly higher at 45 °C.

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.

Acrylamide formation and antioxidant activity in coffee during roasting - A systematic study.

The aim of this study was to investigate the effect of the coffee roasting process on both toxic and some beneficial antioxidant compounds, applying a systematic and broad approach. Arabica and Robusta green coffee beans were roasted in a lab-scale roaster for different times in order to achieve five roasting degrees (from light to dark) and to assess the evolution of acrylamide (AA), trigonelline, nicotinic acid and caffeoylquinic acids contents (determined by HPLC) as well as antioxidant activity (evaluated by Folin-Ciocalteu, FRAP, DPPH, ABTS assays). The results confirmed that the AA levels and antioxidant activity reached a maximum in the first coffee roasting degrees and then decreased prolonging the heating process, both in Arabica and Robusta samples. Nevertheless, the thermal reduction observed was greater for AA compared to antioxidant activity, which was only slightly reduced due to the balance between the degradation and the neoformation of antioxidant compounds.

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.

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.

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 (aw) 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 aw 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.

Influence of Pulsed Electric Field and Ohmic Heating Pretreatments on Enzyme and Antioxidant Activity of Fruit and Vegetable Juices.

The objective of this work was to optimize pulsed electric field (PEF) or ohmic heating (OH) application for carrot and apple mashes treatment at different preheating temperatures (40, 60 or 80 °C). The effect of tissue disintegration on the properties of recovered juices was quantified, taking into account the colour change, the antioxidant activity and the enzyme activity of peroxidase (POD) in both carrot and apple juice and polyphenol oxidase (PPO) in apple juice. Lower ΔE and an increase of the antioxidant activity were obtained for juice samples treated with temperature at 80 °C with or without PEF and OH pretreatment compared with those of untreated samples. The inactivation by 90% for POD and PPO was achieved when a temperature of 80 °C was applied for both carrot and apple mash. A better retention of plant secondary metabolites from carrot and apple mashes could be achieved by additional PEF or OH application. Obtained results are the basis for the development of targeted processing concepts considering the release, inactivation and retention of ingredients.

(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.

The impact of gas mixtures of Argon and Nitrous oxide (N2O) on quality parameters of sardine (Sardina pilchardus) fillets during refrigerated storage.

The effect of modified atmosphere packaging (MAP) with unconventional gas mixtures on the main qualitative parameters of sardine fillets during refrigerated storage was investigated. Four different atmospheres conditions were tested: air; 30% CO2 + 70% N2; 30% CO2 + 70% N2O and 30% CO2 + 70% Ar. All samples were packaged in polypropylene trays sealed with a high barrier film and stored at 2-4 °C for 12 days. The quality and the freshness of sardine fillets packed in MAP were evaluated by microbiological, physical and chemical analyses after 0, 1, 2, 5, 6, 8 and 12 days of the storage period. The 2-thiobarbituric acid-reactive substances (TBARS) values for MAP samples were lower compared to air samples, reaching a final value of 1.09 mg malonaldehyde (MA)/kg and 3.39 mg MA/kg, respectively. The samples packed in Ar reached the fixed threshold for total mesophilic and psychrotrophic bacteria after 12 days of storage, resulting the best MAP condition adopted, able to increase the sardine shelf-life of 3 days with respect to the other tested conditions. Air packed samples showed significantly higher (p < 0.05) Hx content (50 mg/kg) compared to the rest of the MAP samples (20 mg/kg). At the end of the storage period, the sample packed in Ar showed a significantly lower value (p < 0.05) (around 40 mg/kg), than the other MAP 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.

The influence of carrier material on some physical and structural properties of carrot juice microcapsules.

This study investigates the effect of carrier type on the physical and structural properties of microcapsules of pure carrot juice. Low-crystallised maltodextrin (MD), gum arabic (GA), mixtures of MD and GA (1:1; 2:1; 3:1) and whey protein isolate (WPI) were used as carriers. Microencapsulation was carried out in a spray-drier at inlet air temperature of 160°C. Powders were investigated for dry matter, water activity, diameter, carotene content and hygroscopicity. In addition, differential scanning calorimetry (DSC) and time domain nuclear magnetic resonance (TD-NMR) were applied to analyse microcapsules glass transition temperature (Tg). Carrot powders with GA used as a carrier material resulted in better carotenoids retention and higher stability of powders in terms of higher Tg, lower aw and good hygroscopic properties. However, all powders showed a low aw (below 0.26) and high dry matter content (98-99%) indicating a good potential for protection of microencapsulated carotenoids during the storage.

Optimization of Vacuum Impregnation with Calcium Lactate of Minimally Processed Melon and Shelf-Life Study in Real Storage Conditions.

Vacuum impregnation (VI) is a processing operation that permits the impregnation of fruit and vegetable porous tissues with a fast and more homogeneous penetration of active compounds compared to the classical diffusion processes. The objective of this research was to investigate the impact on VI treatment with the addition of calcium lactate on qualitative parameters of minimally processed melon during storage. For this aim, this work was divided in 2 parts. Initially, the optimization of process parameters was carried out in order to choose the optimal VI conditions for improving texture characteristics of minimally processed melon that were then used to impregnate melons for a shelf-life study in real storage conditions. On the basis of a 23 factorial design, the effect of Calcium lactate (CaLac) concentration between 0% and 5% and of minimum pressure (P) between 20 and 60 MPa were evaluated on color and texture. Processing parameters corresponding to 5% CaLac concentration and 60 MPa of minimum pressure were chosen for the storage study, during which the modifications of main qualitative parameters were evaluated. Despite of the high variability of the raw material, results showed that VI allowed a better maintenance of texture during storage. Nevertheless, other quality traits were negatively affected by the application of vacuum. Impregnated products showed a darker and more translucent appearance on the account of the alteration of the structural properties. Moreover microbial shelf-life was reduced to 4 d compared to the 7 obtained for control and dipped samples.

Effect of freezing on microstructure and degree of syneresis in differently formulated fruit fillings.

This study describes the syneresis and its effect on microstructure in fruit fillings within a wide range of the total soluble solids content and with or without hydrocolloids upon freezing. Linear models showed the relevance of the addition of pectin and gellan gum to fillings to prevent syneresis, increasing the water-holding capacity especially after freezing. Microstructural experiments by means of NMR spin-spin relaxometry combined with fluorescence microscopy allowed to observe that the continuous hydrocolloid gel, containing the dispersed solution of native fruit parts with the addition of inulin and sugars, changed its structure/distribution according to the amount of each ingredient and due to the freezing process. Relaxometry results confirmed that hydrocolloids strength was correlated (R(2)>0.92) with water-holding capacity, due to a relationship between the signal given by the water chemically exchanging with biopolymers, and the changes in the degree of syneresis.

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.

A novel fluorescence microscopy approach to estimate quality loss of stored fruit fillings as a result of browning.

The aim of the present study was to estimate the quality deterioration of apple fillings during storage. Moreover, a potentiality of novel time-saving and non-invasive method based on fluorescence microscopy for prompt ascertainment of non-enzymatic browning initiation in fruit fillings was investigated. Apple filling samples were obtained by mixing different quantities of fruit and stabilizing agents (inulin, pectin and gellan gum), thermally processed and stored for 6-month. The preservation of antioxidant capacity (determined by DPPH method) in apple fillings was indirectly correlated with decrease in total polyphenols content that varied from 34±22 to 56±17% and concomitant accumulation of 5-hydroxymethylfurfural (HMF), ranging from 3.4±0.1 to 8±1mg/kg in comparison to initial apple puree values. The mean intensity of the fluorescence emission spectra of apple filling samples and initial apple puree was highly correlated (R(2)>0.95) with the HMF content, showing a good potentiality of fluorescence microscopy method to estimate non-enzymatic browning.

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.