A Comprehensive Study from Cradle-to-Grave on the Environmental Profile of Malted Legumes.

Three representative pulses from the Latium region of Italy (namely, Solco Dritto chickpeas, SDC, Gradoli Purgatory beans, GPB, and Onano lentils, OL) underwent malting to reduce their anti-nutrient content, such as phytic acid and flatulence-inducing oligosaccharides. This initiative targets the current low per capita consumption of pulses. Employing Life Cycle Analysis, their environmental impact was assessed, revealing an overall carbon footprint of 2.8 or 3.0 kg CO2e per kg of malted (M) and decorticated (D) SDCs or GPBs and OLs, respectively. The Overall Weighted Sustainability scores (OWSS) complying with the Product Environmental Footprint method ranged from 298 ± 30 to 410 ± 40 or 731 ± 113 µPt/kg for malted and decorticated SDCs, OLs, or GPBs, indicating an increase from 13% to 17% compared to untreated dry seeds. Land use impact (LU) was a dominant factor, contributing 31% or 42% to the OWSS for MDSDCs or MDOLs, respectively. In MDGPBs, LU constituted 18% of the OWSS, but it was overshadowed by the impact of water use arising from bean irrigation, accounting for approximately 52% of the OWSS. This underscores the agricultural phase's pivotal role in evaluating environmental impact. The climate change impact category (CC) was the second-largest contributor, ranging from 28% (MDSDCs) to 22% (MDOLs), and ranking as the third contributor with 12% of the OWSS for MDGPBs. Mitigation should prioritize the primary impact from the agricultural phase, emphasizing land and water utilization. Selecting drought-tolerant bean varieties could significantly reduce OWSSs. To mitigate climate change impact, actions include optimizing electricity consumption during malting, transitioning to photovoltaic electricity, upgrading transport vehicles, and optimizing pulse cooking with energy-efficient appliances. These efforts, aligning with sustainability goals, may encourage the use of malted and decorticated pulses in gluten-free, low fat, α-oligosaccharide, and phytate-specific food products for celiac, diabetic, and hyperlipidemic patients. Overall, this comprehensive approach addresses environmental concerns, supports sustainable practices, and fosters innovation in pulse utilization for improved dietary choices.

Antinutrient removal in yellow lentils by malting.

BACKGROUND: To improve the current low per capita consumption of lentils, the present study first aimed to minimize the anti-nutrient content of two yellow Moroccan and Italian lentil seeds by resorting to the malting process and then testing the resulting decorticated flours as ingredients in the formulation of gluten-free fresh egg pastas. RESULTS: The most proper operating conditions for the three malting process steps were identified in a bench-top plant. The first (water steeping) and second (germination) steps were studied at 18, 25 or 32 °C. After 2 or 3 h of steeping at 25 °C and almost 24 h of germination, 95-98.8% of the lentil seeds sprouted. By prolonging the germination process to 72 h, the raffinose or phytic acid content was reduced by about 80% or 95% or 27% or 37%, respectively. The third step (kilning) was carried out under fluent dry air at 50 °C for 24 h and at 75 °C for 3 h. The cotyledons of the resulting yellow lentil malts were cyclonically recovered, milled and chemico-physically characterized. CONCLUSION: Both flours were used to prepare fresh egg-pastas essentially devoid of oligosaccharides, and low in phytate (4.6-6.0 mg g-1 ) and in vitro glycemic index (38-41%). However, the cooking quality of the fresh egg pasta made of malted Moroccan lentil flour was higher with respect to its crude protein content and lower with respect to its water solubility index. © 2023 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Assessment of the Malting Process of Purgatory Bean and Solco Dritto Chickpea Seeds.

This study was aimed at minimizing the anti-nutrient content of the Gradoli Purgatory bean (GPB: Phaseolus vulgaris) and Solco Dritto chickpea (SDC: Cicer arietinum) seeds grown in the Latium region of Italy by defining the three steps of their malting process. The water steeping and germination phases were carried out in a 1.0-kg bench-top plant at 18, 25, or 32 °C. By soaking both seeds at 25 °C for 3 h, 95 to 100% of seeds sprouted. There was no need for prolonging their germination process after 72 h, the degradation degree of raffinose in germinated GPBs or SDCs being about 63%, while that of phytic acid being ~32% or 23%, respectively. The steeping and germination kinetics of both seeds were mathematically described via the Peleg and first-order reaction models, respectively. The third step (kilning) was carried out under fluent dry air at 50 °C for 24 h and at 75 °C for 3 h, and yielded cream-colored malted seeds, the cotyledons of which were cyclonically separated from the cuticles and finally milled. Owing to their composition, the decorticated malted pulse flours might be used in the formulation of specific gluten-free food products high in raw proteins and low in phytate, α-oligosaccharides and in vitro glycemic index (GI). Even if their low GI trait was preserved after malting, only the GPB malt flour having a resistant starch-to-total starch ratio ≥ 14% has the potential to be labeled with the health claim for improving postprandial glucose metabolism according to EU Regulation 432/2012.

Semiempirical modeling of a traditional wood-fired pizza oven in quasi-steady-state operating conditions.

Wood-fired ovens are mandatorily used to bake the Neapolitan pizza. Unfortunately, they are still empirically operated. In this work, a pilot-scale wood-fired oven was kept operating in quasi-steady-state conditions. Once the combustion reaction of oak logs had been modeled, the composition of flue gas measured, and the external oven wall and floor temperatures thermographically scanned, it was possible to check for the material and energy balances and, thus, assess that the heat loss rates through flue gas and insulated oven chamber were, respectively, equal to 46% and 26% of the energy supplied by burning firewood. The enthalpy accumulation rate in the internal fire brick oven chamber amounted to about 3.4 kW, this being adequate to keep not only the temperatures of the oven vault and floor practically constant but also to bake one or two pizzas at the same time. Such a rate was predicted by contemplating the simultaneous heat transfer mechanisms of radiation and convection between the oven vault and floor surface areas. The efficacy of the semiempirical modeling developed here was further tested by reconstructing quite accurately the time course of water heating in aluminum trays with a diameter near to that of a typical Neapolitan pizza. The heat flow from the oven vault to the water-containing tray was of the radiative and convective types for about 73% and 15%, whereas the residual 12% was of the conductive type from the oven floor. PRACTICAL APPLICATION: Despite wood-fired ovens are largely used in the restaurant and food service industry, their operation is highly dependent on the operator's ability. This study shows how the heat loss rates through flue gas and insulated oven chamber can be assessed, and how the enthalpy accumulation rate in the internal fire brick oven chamber can be predicted by accounting for the simultaneous heat transfer mechanisms of radiation and convection between the oven vault and floor surface areas. The efficacy of this semi-empirical modelling was further checked for via some water heating tests.

Phenomenology of Neapolitan Pizza Baking in a Traditional Wood-Fired Oven.

Despite Neapolitan pizza is a globally renowned Italian food, its obligatory baking in wood-fired ovens has so far received little attention in the scientific community. Since heat transfer during pizza baking is not at all uniform, the main aim of this work was to analyze the phenomenology of Neapolitan pizza baking in a pilot-scale wood-fired pizza oven operating in quasi steady-state conditions. The different upper area sections of pizza covered or not by the main topping ingredients (i.e., tomato puree, sunflower oil, or mozzarella cheese), as well the bottom of the pizza and the growth of its raised rim, were characterized by visual colorimetric analysis, while the time course of their corresponding temperatures was monitored using an infrared thermal scanning camera. The maximum temperature of the pizza bottom was equal to 100 ± 9 °C, while that of the upper pizza side ranged from 182 °C to 84 or 67 °C in the case of white pizza, tomato pizza, or margherita pizza, respectively, mainly because of their diverse moisture content and emissivity. The pizza weight loss was nonlinearly related to the average temperature of the upper pizza side. The formation of brown or black colored areas on the upper and lower sides of baked pizza was detected with the help of an electronic eye. The upper side exhibited greater degrees of browning and blackening than the lower one, their maximum values being about 26 and 8%, respectively, for white pizza. These results might help develop a specific modelling and monitoring strategy to reduce variability and maximize the quality attributes of Neapolitan pizza.

Performance characterization of a traditional wood-fired pizza oven.

Neapolitan pizza, a renowned Italian food recognized as one of the traditional specialties guaranteed (TSG) by European Commission Regulation no. 97/2010, should be exclusively baked in wood-fired ovens for approximately 90 s. Despite its extensive use in restaurants and rotisserie shops all around the world, such equipment has been very poorly studied thus far. The aims of this study were to characterize the operation of a pilot-scale wood-fired pizza oven from its start-up phase to its baking operation and assess its thermal efficiency. To manage brick firing, the oven was lighted at a firewood feed rate (Qfw ) of 3 kg/h for just 1 h on the first day, 2 h on the second day, 4 h on the third day, and approximately 8 h on the fourth day. Independent of its lighting frequency, after 4-6 h, the oven vault or floor temperature approached an equilibrium value of 546 ± 53°C or 453 ± 32°C, respectively. The initial oven floor temperature gradient was linearly related to Qfw , while the maximum floor temperature tended to an asymptotic value of 629 ± 43°C at Qfw = 9 kg/h. The well-known water boiling test was adapted to assess the heat absorbed by a prefixed amount of water when the pizza oven was operating in pseudosteady-state conditions at Qfw = 3 kg/h. The thermal efficiency of this oven was 13 ± 4%, and this value was further confirmed by other baking tests with four different white and tomato pizza products. PRACTICAL APPLICATION: Although wood-fired pizza ovens are largely used all over the world, little is known about their transitory and pseudosteady-state regime performance. This study shows how to perform the start-up procedure of pilot-scale equipment and, independent of the operator's ability, how to achieve pseudosteady-state conditions using different firewood feed rates. Finally, its thermal efficiency was assessed by water heating and pizza baking tests, which allowed a rough estimation of firewood consumption.

Characterization of Fresh Pasta Made of Common and High-Amylose Wheat Flour Mixtures.

This study aims to assess the main biochemical, technological, and nutritional properties of a few samples of fresh pasta composed of commercial common wheat flour blended with increasing percentages, ranging from 0 to 100%, of high-amylose wheat flour. Although the technological parameters of such samples remained practically constant, fresh pasta samples including 50 to 100% of high-amylose wheat flour were classifiable as foods with a low in vitro glycemic index of about 43%. However, only fresh pasta made of 100% high-amylose wheat flour exhibited a resistant starch-to-total starch ratio greater than 14% and was therefore eligible to claim a physiological effect of improved glucose metabolism after a meal, as according to EU Regulation 432/2012.

Environmental Profile of a Novel High-Amylose Bread Wheat Fresh Pasta with Low Glycemic Index.

To improve glycemic health, a high-amylose bread wheat flour fresh pasta characterized by a low in vitro glycemic index (GI) and improved post-prandial glucose metabolism was previously developed. In this study, well-known life cycle analysis software was used in accordance with the PAS 2050 and mid- and end-point ReCiPe 2016 standard methods to assess, respectively, its carbon footprint and overall environmental profile, as weighted by a hierarchical perspective. Even if both eco-indicators allowed the identification of the same hotspots (i.e., high-amylose bread wheat cultivation and consumer use of fresh pasta), the potential consumer of low-GI foods should be conscious that the novel low-GI fresh pasta had a greater environmental impact than the conventional counterpart made of common wheat flour, their corresponding carbon footprint or overall weighted damage score being 3.88 and 2.51 kg CO2e/kg or 184 and 93 mPt/kg, respectively. This was mainly due to the smaller high-amylose bread wheat yield per hectare. Provided that its crop yield was near to that typical for common wheat in Central Italy, the difference between both eco-indicators would be not greater than 9%. This confirmed the paramount impact of the agricultural phase. Finally, use of smart kitchen appliances would help to relieve further the environmental impact of both fresh pasta products.

Effect of cooking temperature on cooked pasta quality and sustainability.

BACKGROUND: Everyday pasta cooking has a large environmental impact. The aims of this work were to assess the effect of cooking temperatures (TC ) that were lower than the water boiling point (TBW ) on the main chemico-physical quality parameters of two pasta shapes (i.e., ziti and spaghetti) cooked at the conventional and minimum water-to-pasta ratios, as well as their optimum cooking time (OCT), cooking energy consumption, and carbon footprint, by using a novel eco-sustainable pasta cooker. RESULTS: Once the effect of TC on OCT had been modeled in accordance with the Bigelow model, it was possible to estimate that the energy saved to heat the cooking water from ambient temperature to a lower temperature than TBW was smaller than the extra energy needed to complete the pasta cooking phase. After several cooking trials, the water uptake, cooking loss, textural properties, and thickness of the central nerve (as observed with a scanning electronic microscope) of cooked pasta were found to be independent of TC in the range of 85-98 °C. CONCLUSIONS: By using smaller amounts of water (~3 L kg-1 ) and cooking at 85 °C with the eco-sustainable pasta cooker, the energy consumption reduced from the default value of 2.8 kWh kg-1 to ~0.45 kWh kg-1 and GHG emissions to about one sixth of those resulting from the use of the average European home appliances. © 2021 Society of Chemical Industry.

Innovative Rough Beer Conditioning Process Free from Diatomaceous Earth and Polyvinylpolypyrrolidone.

In large-sized breweries, rough beer clarification is still carried out using Kieselguhr filters notwithstanding their environmental and safety implications. The main aim of this work was to test an innovative rough beer clarification and stabilization process involving enzymatic treating with Brewers Clarex®, centrifuging, rough filtering across 1.4-µm ceramic hollow-fiber membrane at 30 °C, and fine filtering through 0.45-µm cartridge filter. When feeding an enzymatically-pretreated and centrifuged rough beer with permanent haze (HP) of 2 or 14 European Brewery Convention unit (EBC-U), its primary clarification under periodic CO2 backflushing yielded a permeate with turbidity of 1.0-1.5 EBC-U at a high permeation flux (2.173 ± 51 or 593 ± 100 L m-2 h-1), much greater than that typical of powder filters. The final beer was brilliant (HP = 0.57 ± 0.08 EBC-U) with almost the same colloidal stability of the industrial control and an overall log reduction value (~5.0 for the selected beer spoilage bacterium or 7.6 for the brewing yeast) in line with the microbial effectiveness of current sterilizing membranes. It was perceived as significantly different in flavor and body from the industrial control at a probability level of 10% by a triangle sensory test, as more likely related to the several lab-scale beer-racking steps used than to the novel process itself.

Cradle-to-grave carbon footprint of dried organic pasta: assessment and potential mitigation measures.

BACKGROUND: In several Environmental Product Declarations, the business-to-business carbon footprint (CFCDC ) of durum wheat semolina dried pasta ranged from 0.57 to 1.72 kg carbon dioxide equivalent (CO2e ) kg-1 . In this work, the business-to-consumer carbon footprint (CFCG ) of 1 kg of dry decorticated organic durum wheat semolina pasta, as packed in 0.5 kg polypropylene bags by a South Italian medium-sized pasta factory in the years 2016 and 2017, was assessed in compliance with the Publicly Available Specification 2050 standard method. RESULTS: Whereas CFCDC was mostly conditioned by the greenhouse gases emitted throughout durum wheat cultivation (0.67 vs 1.12 kg CO2e kg-1 ), CFCG was mainly dependent on the use and post-consume phases (0.68 vs 1.81 kg CO2e kg-1 ). CFCG was more or less affected by the pasta types and packing formats used, since it varied from +0.3 to +14.8% with respect to the minimum score estimated (1.74 kg CO2e kg-1 ), which corresponded to long goods packed in 3 kg bags for catering service. Once the main hotspots had been identified, CFCG was stepwise reduced by resorting to a series of mitigation actions. CONCLUSION: Use of more eco-sustainable cooking practices, organic durum wheat kernels resulting from less impacting cultivation techniques, and renewable resources to generate the thermal and electric energy needs reduced CFCG by about 58% with respect to the above reference case. Finally, by shifting from road to rail freight transport and shortening the supply logistics of dry pasta and grains, a further 5% reduction in CFCG was achieved. © 2019 Society of Chemical Industry.

Reducing the cooking water-to-dried pasta ratio and environmental impact of pasta cooking.

BACKGROUND: During daily pasta cooking, the general consumer pays little attention to water and energy issues. The present study aimed to measure the cooking quality and environmental impact of a standard format of dry pasta by varying the water-to-dried pasta ratio (WPR) from 12 to 2 L kg-1 . RESULTS: In the above WPR range, the cooked pasta water uptake (1.3 ± 0.1 g g-1 ), cooking loss (0.037 ± 0.009 g g-1 ) and degree of starch gelatinization (11.2 ± 0.8%) were approximately constant, whereas the main Texture Analysis parameters (eg, cooked pasta hardness at 30% and 90% deformation, and resilience) showed no statistically significant difference. As the WPR was reduced from 12 to 2 L kg-1 , the specific electric energy consumption linearly decreased from 1.93 to 0.39 Wh g-1 and the carbon footprint and eutrophication potential of pasta cooking lessened by approximately 80% and 50%, respectively. CONCLUSION: Cooking dry pasta in a large excess of water (ie, 10 L kg-1 ), as commonly suggested by the great majority of pasta manufacturers, might be pointless. Such a great mitigation with respect to the environmental impact of pasta cooking should be checked further for other commercial pasta formats and would highlight the need for novel and more suitable pasta cookers than those currently in use. © 2018 Society of Chemical Industry.

Towards a Kieselguhr- and PVPP-Free Clarification and Stabilization Process of Rough Beer at Room-Temperature Conditions.

In this work, the main constraint (that is, beer chilling and chill haze removing) of the current beer conditioning techniques using Kieselguhr filtration and Polyvinylpolypyrrolidone (PVPP) treatment was overcome by developing a novel higher-throughput conditioning process, operating at room temperatures with no use of filter aids. The effect of filtration temperature (TF ) in the range of 0 to 40 °C on the hydraulic permeability of ceramic hollow-fiber (HF) membranes with nominal pore size of 0.2 to 1.4 µm, as well as on their limiting permeation flux (J* ) when feeding precentrifuged rough beer, was preliminarily assessed. When using the 1.4-µm HF membrane operating at TF ≥ 20 °C, it was possible to enhance the average permeation flux at values (676 to 1844 L/m2 /h), noticeably higher than those (250 to 500 L/m2 /h) characteristics of conventional powder filtration. Despite its acceptable permanent haze, the resulting beer permeate still exhibited colloidal instability. By resorting to the commercial enzyme preparation Brewers Clarex® before beer clarification, it was possible to significantly improve its colloidal stability as measured using a number of European Brewing Convention forcing tests, especially with respect to that of precentrifuged rough beer by itself. By combining the above enzymatic treatment with membrane clarification at 30 °C across the ceramic 1.4-µm HF membrane module, it was possible to limit the haze development due to chilling, sensitive proteins, and alcohol addition to as low as 0.78, 4.1, and 4.0 EBC-U, respectively, the enzymatic treatment being by far more effective than that using PVPP. PRACTICAL APPLICATION: A novel Kieselguhr- and PVPP-free rough beer conditioning process at room temperatures was set up. By submitting precentrifuged rough beer to commercial preparation Brewers Clarex ® and then to membrane clarification at 30 °C across a ceramic 1.4-µm hollow-fiber membrane module, it was possible to obtain a clear and stable beer with a throughput (1306 ± 72 L/m2 /h) by far higher than that (250 to 500 L/m2 /h) characterizing the current powder filters. The haze development due to chilling, sensitive proteins, and alcohol adding was by far lower than that observed when microfiltering PVPP-pretreated rough beer.

Beer Clarification by Novel Ceramic Hollow-Fiber Membranes: Effect of Pore Size on Product Quality.

In this work, the crossflow microfiltration performance of rough beer samples was assessed using ceramic hollow-fiber (HF) membrane modules with a nominal pore size ranging from 0.2 to 1.4 µm. Under constant operating conditions (that is, transmembrane pressure difference, TMP = 2.35 bar; feed superficial velocity, vS = 2.5 m/s; temperature, T = 10 °C), quite small steady-state permeation fluxes (J* ) of 32 or 37 L/m2 /h were achieved using the 0.2- or 0.5-µm symmetric membrane modules. Both permeates exhibited turbidity <1 EBC unit, but a significant reduction in density, viscosity, color, extract, and foam half-life with respect to their corresponding retentates. The 0.8-µm asymmetric membrane module might be selected, its corresponding permeate having quite a good turbidity and medium reduction in the aforementioned beer quality parameters. Moreover, it exhibited J* values of the same order of magnitude of those claimed for the polyethersulfone HF membrane modules currently commercialized. The 1.4-µm asymmetric membrane module yielded quite a high steady-state permeation flux (196 ± 38 L/m2 /h), and a minimum decline in permeate quality parameters, except for the high levels of turbidity at room temperature and chill haze. In the circumstances, such a membrane module might be regarded as a real valid alternative to conventional powder filters on condition that the resulting permeate were submitted to a final finishing step using 0.45- or 0.65-µm microbially rated membrane cartridges prior to aseptic bottling. A novel combined beer clarification process was thus outlined.

Assessing the Potential Content of Ethyl Carbamate in White, Red, and Rosé Wines as a Key Factor for Pursuing Urea Degradation by Purified Acid Urease.

The ethyl carbamate (EC) content of a wine after a given temperature-time storage was theoretically predicted from the potential concentration of ethyl carbamate (PEC), as determined via an accelerated EC formation test. Such information was used to decide whether an enzymatic treatment was needed to reduce the wine urea level before bottling/aging. To this end, 6 white, red, and rosé wines, manufactured in Italy as such or enriched with urea, were tested for their PEC content either before or after enzymatic treatment using a purified acid urease preparation derived from Lactobacillus fermentum. The treatment was severely affected by the total phenolic content (TP) of the wine, the estimated pseudo-first-order kinetic rate constant for NH3 formation reducing by a factor of approximately 2000 as the TP increased from 0 to 1.64 g L(-1) . Such a sensitivity to TP was by far greater than that pertaining to a killed cell-based enzyme preparation used previously. Urea hydrolysis was successful at reducing EC concentration in wines with low levels of TP and other EC precursors.

Screening, isolation, and characterization of glycosyl-hydrolase-producing fungi from desert halophyte plants.

Fungal strains naturally occurring on the wood and leaves of the salt-excreting desert tree Tamarix were isolated and characterized for their ability to produce cellulose- and starch-degrading enzymes. Of the 100 isolates, six fungal species were identified by ITS1 sequence analysis. No significant differences were observed among taxa isolated from wood samples of different Tamarix species, while highly salt-tolerant forms related to the genus Scopulariopsis (an anamorphic ascomycete) occurred only on the phylloplane of T. aphylla. All strains had cellulase and amylase activities, but the production of these enzymes was highest in strain D, a Schizophyllum-commune-related form. This strain, when grown on pretreated Tamarix biomass, produced an enzymatic complex containing levels of filter paperase (414 +/- 16 IU/ml) that were higher than those of other S. commune strains. The enzyme complex was used to hydrolyze different lignocellulosic substrates, resulting in a saccharification rate ofpretreated milk thistle (73.5 +/- 1.2%) that was only 10% lower than that obtained with commercial cellulases. Our results support the use of Tamarix biomass as a useful source of cellulolytic and amylolytic fungi and as a good feedstock for the economical production of commercially relevant cellulases and amylases.

Screening, isolation, and characterization of glycosyl-hydrolase-producing fungi from desert halophyte plants

Fungal strains naturally occurring on the wood and leaves of the salt-excreting desert tree Tamarix were isolated and characterized for their ability to produce cellulose- and starch- degrading enzymes. Of the 100 isolates, six fungal species were identified by ITS1 sequence analysis. No significant differences were observed among taxa isolated from wood samples of different Tamarix species, while highly salt-tolerant forms related to the genus Scopulariopsis (an anamorphic ascomycete) occurred only on the phylloplane of T. aphylla. All strains had cellulase and amylase activities, but the production of these enzymes was highest in strain D, a Schizophyllum-commune- related form. This strain, when grown on pretreated Tamarix biomass, produced an enzymatic complex containing levels of filter paperase (414 ± 16 IU/ml) that were higher than those of other S. commune strains. The enzyme complex was used to hydrolyze different lignocellulosic substrates, resulting in a saccharification rate of pretreated milk thistle (73.5 ± 1.2 %) that was only 10 % lower than that obtained with commercial cellulases. Our results support the use of Tamarix biomass as a useful source of cellulolytic and amylolytic fungi and as a good feedstock for the economical production of commercially relevant cellulases and amylases (AU)

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Assessment of quality-assured Tarocco orange fruit sorting rules by combined physicochemical and sensory testing.

BACKGROUND: The aim of this study was to extract a sorting rule for Tarocco orange fruit from several physicochemical and sensory tests performed on a marketable lot of 399 Tarocco orange fruits. RESULTS: The elastic tension at 5% strain (T5 ) was found to be linearly correlated (r = 0.65) with the Magness-Taylor (MT) index. Thus T5 was regarded as a non-destructive parameter quantifying fruit firmness and used to categorise the aforementioned lot in three different firmness classes, high (HF), medium (MF) and low (LF). Only the MT index, fruit rind thickness near the fruit peduncle, lightness coefficient and yellow/blue hue component of the orange flesh, as well as total soluble solid content, confirmed the validity of this discrimination at the significance level of 5%. Sensory professionals recognised the greater compactness (7 ± 2) but lower ease of peeling (4 ± 2) and segment separation (4 ± 2) of the HF oranges with respect to the corresponding sensory attributes of orange fruits grouped in the MF and LF classes. CONCLUSION: To limit the costly rejection of Tarocco orange fruit considered too soft, especially after long-term shipping, it would be reasonable to select only fruits characterised by a compressive force or tension at 5% strain in the range 23-41 N or 300-540 N m⁻¹ respectively.

Immobilization/stabilization of acid urease on Eupergit® supports.

The adsorption capacity and immobilization rate of two Eupergit® supports for acid urease was studied by varying the ionic strength and enzyme preparation concentration in the immobilizing solution at pH 7. Eupergit® C250 L yielded a series of derivatives with enzyme loadings (Y(P/B)) ranging from 48 to 171 mg of bovine serum albumin equivalent (BSAE) per gram of dry support (ds). Use of drastic postimmobilization conditions at pH 9 for 3-9 days yielded a slight decrease (8-14%) in the initial activity of immobilized enzymes and a limited increase in the stabilization factor (1.1-1.5), as assessed by accelerated aging tests at 65 °C. Further storage tests at 4 °C in the wet state showed that the activity of several derivatives either stabilized or not was practically constant for as long as 547 days. Both free enzyme and immobilized acid urease derivatives exhibited a kinetic pattern of the Michaelis-Menten type. Using the Eadie-Hofstee diagram, the specific ammonia formation rate constant for free (k(cat)) or immobilized (k'(cat)) enzyme resulted to be little affected by immobilization (k(cat) ≈ k'(cat) ≈ 18.86 ± 0.34 IU/mg BSAE), whereas the apparent Michaelis constant for immobilized enzymes exhibited a statistically significant increase at P < 0.05 from the intrinsic value (2.55 ± 0.14 mM) for free enzyme to 5.38 ± 0.87 mM as Y(P/B) increased to 171 mg BSAE/g ds. By estimating the observable Thiele modulus (Φ(obs) ), the activity of the biocatalyst with the greatest enzyme loading at the lowest urea concentrations tested (0.833 mM) was reduced by a factor of about 2 due to internal diffusional limitations. By operating in the pseudofirst-order regime with immobilized derivatives at Y(P/B) about 126 mg BSAE/g ds, their activity after grinding was no more limited by intraparticle diffusion and approached the value for free enzyme.

Development and testing of a novel lab-scale direct steam-injection apparatus to hydrolyse model and saline crop slurries.

In this work, a novel laboratory-scale direct steam-injection apparatus (DSIA) was developed to overcome the main drawback of the conventional batch-driven lab rigs, namely the long time needed to heat fiber slurry from room to reaction temperatures greater than 150 °C. The novel apparatus mainly consisted of three units: (i) a mechanically-stirred bioreactor where saturated steam at 5-30 bar can be injected; (ii) an automatic on-off valve to flash suddenly the reaction medium after a prefixed reaction time; (iii) a cyclone separator to recover the reacted slurry. This system was tested using 0.75 dm³ of an aqueous solution of H2SO4 (0.5%, v/v) enriched with 50 kg m⁻³ of either commercial particles of Avicel® and Larch xylan or 0.5 mm sieved particles of Tamarix jordanis. Each slurry was heated to about 200 °C by injecting steam at 28 bar for 90 s. The process efficiency was assessed by comparing the dissolution degree of suspended solid (Y(S)), as well as xylose (Y(X)), glucose (Y(G)), and furfural (Y(F)) yields, with those obtained in a conventional steam autoclave at 130 °C for 30 or 60 min. Treatment of T. jordanis particles in DSIA resulted in Y(S) and Y(G) values quite similar to those obtained in the steam autoclave at 130 °C for 60 min, but in a less efficient hemicellulose solubilization. A limited occurrence of pentose degradation products was observed in both equipments, suggesting that hydrolysis predominated over degradation reactions. The susceptibility of the residual solid fractions from DSIA treatment to a conventional 120 h long cellulolytic treatment using an enzyme loading of 5.4 FPU g⁻¹ was markedly higher than that of samples hydrolysed in the steam autoclave, their corresponding glucose yields being equal to 0.94 and 0.22 g per gram of initial cellulose, respectively. Thus, T. jordanis resulted to be a valuable source of sugars for bioethanol production as proved by preliminary tests in the novel lab rig developed here.