Enrichment of wheat flour with Spirulina. Evaluation of thermal damage to essential amino acids during bread preparation.

Microalgae and cyanobacteria represent a sustainable and valuable source of essential amino acids and bio-active molecules (e.g. poly-unsaturated fatty acids and antioxidants) which, if added to staple food, could enrich its nutritional profile and the human diet. In this study, two different composite mixtures were obtained by adding different percentages (1% and 2%) of Spirulina powder to "Italian type 1" semi-whole wheat flour (W = 300) after which the chemical, physical, alveographic, and rheological parameters were subsequently analyzed. Spirulina powder did not cause drastic changes at the rheological level when added up to 2%. Furthermore, the concentration of proteins significantly increased in the samples enriched with 1% Spirulina (3.17%) and 2% Spirulina (5.12%), while at the same time the gluten content decreased by 5.62% and 7.41%, respectively. The total amount of essential amino acids in the samples enriched with 1% and 2% Spirulina (48,209 and 55,286 mgaa/kgDW, respectively), was higher in comparison with 45,433 mgaa/kgDW of the control, and those concentrations were maintained after the baking process. Spirulina powder confirmed the hypothesis of being able to improve the supply of essential amino acids that is lacking in wheat flour. The next steps include an investigation into the sensory and liking characteristics of the product.

Partitioning of trace elements in the tissues of Mediterranean mussels (Mytilus galloprovincialis) sampled from industrial sites along the Algerian coast.

This research was aimed at evaluating the seasonal partitioning of Zn, Se, As, Cu, and Co in the tissues of Mytilus galloprovincialis sampled at two industrial sites along the Algerian coast. Adult mussels were seasonally collected from two sites over the course of a whole year. The gills, digestive glands, gonads, and remaining soft tissues were analyzed through ICP-MS. The observations led to identifying metals ranges (µg g-1Dry Weight) of 67.17-395.51 (Zn), 2.18-12.74 (Se), 7.81-28.61 (As), 3.32-155.91 (Cu), and 0.10-3.59 (Co) in the various tissues. The highest concentrations were found in the digestive glands and gills as compared to the gonads and remaining soft tissues. Distinct patterns of metals partitioning were found: indeed, As and Co concentrations were higher in the digestive glands, while Se and Zn concentrations were higher in the gills. Many of the mussels samples resulted contaminated, therefore potentially posing a considerable health risk to consumers.

Functionalization and use of grape stalks as poly(butylene succinate) (PBS) reinforcing fillers.

Grape stalks are a lignocellulosic biomass, which is a very complex material, whose easy and profitable fractionation to obtain its basic components is still not available. Therefore, alternative ways to try and make use of grape stalks are currently being explored. In the present study, the possible use of dried and milled grape stalks as filler in bio-composites was assessed using polybutylene succinate as a basic polymer. The tensile specimens produced using 10% grape stalk powder as it is and functionalized through pre-extrusion acetylation and silylation, and silylation in situ were characterized for their structural, mechanical, thermal, morphological, and color properties. The bio-composites showed to be stiffer than the control polymer, with an increase of Young's modulus from 616 MPa to 732 MPa in the specimens obtained with acetylated grape stalk powder. This led to a potentially new method to valorize by-products of the wine industry such as grape stalks in order to recover raw materials which could prove useful in the biomaterials and bio-composites sector.

Protein films from black soldier fly (Hermetia illucens, Diptera: Stratiomyidae) prepupae: effect of protein solubility and mild crosslinking.

BACKGROUND: This work evaluated the performances of protein-based bioplastics obtained from black soldier fly (Hermetia illucens) prepupae. Protein films were synthesized by film casting, using both the whole proteins and their soluble fraction at pH = 10. The effects of glycerol as a plasticizer and of citric acid as a mild crosslinker on film properties were also evaluated. RESULTS: Films obtained using the soluble protein fraction were the strongest, as well as the most homogeneous and transparent ones. Protein mild crosslinking improved film tensile properties, especially in films obtained with the whole protein fraction. Non-crosslinked samples had a high affinity with water while crosslinking almost eliminated the ability of films to absorb water. All protein-based films proved to be effective barriers to red light (transmittance less than 2%). CONCLUSIONS: Bioplastics derived from black soldier fly prepupae may find applications in the agricultural sector (biodegradable pots, mulching films, utensils) and deserve to be tested for food and non-food packaging. © 2021 Society of Chemical Industry.

Lipid profile and growth of black soldier flies (Hermetia illucens, Stratiomyidae) reared on by-products from different food chains.

BACKGROUND: The total amount of bio-waste produced annually in the EU by the food and beverage chains is estimated at 37 billion kg. The use of insects for the valorization of by-products from these value chains may represent a sustainable solution. This study aimed to investigate the by-products obtained from different food chains and used for the rearing of black soldier fly (BSF) prepupae, and to evaluate the content and profile of the lipid extracted from the prepupae and outline its possible applications. The substrates used in this experiment were: (i) industrial by-products (brewery spent grains, cows' milk whey, grape stalks, and tomato peels and seeds) and (ii) by-products from retailers (bread dough, fish scraps, and spent coffee ground). Fat extracted from prepupae using an adjusted Folch method was used for total lipid content and fatty acid profile. RESULTS: The best larval performances were obtained from beer (0.22 gweight per prepupa), tomato (0.19 gweight per prepupa), and cheese (0.14 gweight per prepupa) food-chain by-products. The extremely different compositions of the substrates were reflected in the differentiated lipid profile of the BSF prepupae and in the range of ratios between unsaturated and saturated fatty acids, which varied from 0.37 for cows' milk whey to 1.34 for tomato peels and seeds. CONCLUSION: The lipids, proteins, and chitin extracted from prepupae are high-value bio-based products that could be used in the feed / food industry or for the development of innovative biomaterials, such as biodiesel. These results suggest that food-chain by-products are the best candidates for insect-bioconversion purposes. © 2020 Society of Chemical Industry.

Determination of four Alternaria alternata mycotoxins by QuEChERS approach coupled with liquid chromatography-tandem mass spectrometry in tomato-based and fruit-based products.

A liquid chromatography-tandem mass spectrometry method for the determination of four Alternaria toxins, i.e. alternariol, alternariol monomethyl ether, tentoxin, and tenuazonic acid in tomato-based and fruit-based products was developed using a QuEChERs approach for the extraction of the mycotoxins. To optimise the QuEChERs extraction, several parameters were tested: types of QuEChERs pouches, sample weights, quantities of added water, use of dispersive SPE as a purification step, types of solvent and conditions of shaking. The method showed good linearity (R2 > 0.997) and precision (RSD% < 10) for all analytes. Tenuazonic acid showed very good recovery (98.8%-108.9%) for tomato-based products, as well as for fruit-based products. The method was successfully applied to 57 samples collected from the Italian market. Tenuazonic acid was found in appreciable concentrations in some products. The highest value was found in a tomato sauce sample (814 µg/kg).

Study of the repartition of phthalate esters during distillation of wine for spirit production.

Due to health concerns and legal matters, an investigation to limit phthalates esters (PEAs) in spirits is necessary. A lab still was used to perform pilot distillations according to the official method for brandy production in order to explore the repartition into the distilled fractions of each PAE. The process was divided in two steps: a première chauffe and a bonne chauffe. The former step included the cut into heads, heart and tails, while the latter into heads, brandy, secondes, and tails. The behaviour of each PAE during distillation was affected by its own chemical nature. Dibutyl phthalate (DBP) was entirely carried over into the distillate, while bis(2-ethylhexyl) phthalate (DEHP) only partially, and diisononyl phthalate (DINP) accumulated in the stillage. During the bonne chauffe, DBP and DEHP accumulated in the secondes more than in the brandy. A rectification step of the secondes was demonstrated to considerably reduce PAEs concentration.

Single step extraction and derivatization of intramuscular lipids for fatty acid Ultra Fast GC analysis: application on pig thigh.

Two different methods for single step transesterification from pig meat without fat extraction have been tested. Freeze-drying of the meat with and without anhydrous salt, followed by a base-catalyzed transmethylation (KOH/MeOH) was carried out. Both methods were compared with the standard Folch procedure of fat extraction followed by transmethylation. The methods were tested on a complete sample set of biceps femoris of pig thigh, used for the production of dry-cured ham. The set was divided in three subgroups according to total fat content. Both derivatization protocols on freeze-dried pork muscle were proven to be a valid alternative to the Folch procedure for FAME analysis. Freeze-drying method offered several advantages in comparison with the Folch procedure, including a lower solvent requirement, and process temperature, as well as considerable saving of time. In freeze-drying, the addition of an anhydrous salt (Na2SO4) gave more friable samples which resulted in higher yields for some fatty acids, particularly evident in the case of tissues with high lipid content.

Application of a stir bar sorptive extraction method for the determination of volatile compounds in different grape varieties.

BACKGROUND: Stir bar sorptive extraction (SBSE) has been employed for the analysis of aroma compounds directly from Spanish and Italian grape extracts. The extraction conditions have been optimized using a statistical approach, obtaining results that improve the current state of the art. RESULTS: The proposed analytical conditions were: sample volume 40 mL, extraction time 80 min, 25% (w/v) NaCl and stirring speed 750 rpm using 20 mm × 0.5 mm stir bars. Performance characteristics of the SBSE procedure were further studied and showed correlation coefficients, detection and quantification limits, linear ranges, recoveries and precision values adequate for analysing these compounds in grapes. Twenty-four grape varieties (aromatic and non-aromatic) were analysed. Statistically significant differences (P < 0.05) according to geographical origin were found, being derived mainly from the terpenoid content. By principal component analysis it was possible to note that the terpenoids were more effective in the separation of the non-aromatic samples, showing negative and positive scores for Italian and Spanish grapes, respectively. CONCLUSION: For non-aromatic grape varieties, the factor 'geographic location' was the most significant, thus corroborating the high influence of this parameter on the volatile composition of grapes and therefore on the genuineness of wines. © 2016 Society of Chemical Industry.

Determination of phthalate esters in distillates by ultrasound-vortex-assisted dispersive liquid-liquid micro-extraction (USVADLLME) coupled with gas chromatography/mass spectrometry.

A method for the extraction of phthalate esters (PAEs) by Ultrasound-Vortex-Assisted Dispersive Liquid-Liquid Micro-Extraction (USVADLLME) approach was optimised and applied for the first time to a historical series of brandies. These contaminants are widely spread in the environment as a consequence of about half century of use in different fields of applications. The concern about these substances and the recent legal restrictions of China in distillates import need a quick and sensitive method for their quantification. The proposed method, moreover, is environmentally oriented due to the disposal of micro-quantities of solvent required. In fact, sub-ppm-limits of detection were achieved with a solvent volume as low as 160µL. The analysed samples were within the legal limits, except for some very ancient brandies whose contamination was probably due to a PAEs concentration effect as a consequence of long ageing and for the use of plastic pipelines no more operative.

Determination of acrylamide in dried fruits and edible seeds using QuEChERS extraction and LC separation with MS detection.

Acrylamide is a carcinogenic and neurotoxic process contaminant that is generated from food components during heat treatment, while it is absent in raw foodstuffs. Its level in food arouses great concern. A method for acrylamide extraction and determination in dried fruits (dried prunes and raisins) and edible seeds (almonds, hazelnuts, peanuts, pine nuts, pistachios, and walnuts) using a QuEChERS-LC-ESI-MS-Triple Quadrupole approach was set up. Linearity, sensitivity, accuracy, and precision of the method were satisfactory. Dried prunes and peanuts were the only samples appreciably contaminated, 14.7-124.3 and 10.0-42.9µg/kg, respectively, as a consequence of the drying process. In fact, prunes are dried at 70-80°C for a quite long time (24-36h), while peanuts undergo a roasting process at 160-180°C for 25-30min. The relative standard deviations, accuracy, LOD, and LOQ show that the method provides a reliable approach to acrylamide determination in different matrices.

Ampelographic and chemical characterization of Reggio Emilia and Modena (northern Italy) grapes for two traditional seasonings: 'saba' and 'agresto'.

BACKGROUND: 'Saba' and 'agresto' are traditional Italian products both based on unfermented grape juices that are concentrated by heating. The former is obtained from ripe grapes and the latter from unripe grapes. In this work, we have characterized the main red-skinned (Ancellotta, Fortana, Lambrusco di Sorbara, Lambrusco grasparossa, Lambrusco salamino and Uva Tosca) and white-skinned (Lugliatica, Spergola, Trebbiano di Spagna and Trebbiano modenese) cultivars used for 'saba' and 'agresto' production, focusing on the variability expressed by ampelographic traits, physical and chemical parameters and anthocyanin profile. RESULTS: The cultivars examined were effectively discriminated on the basis of their different composition profile by analysis of variance and principal component analysis. In particular, a peculiar anthocyanin profile was traced by absolute and relative values for each cultivar. The identification of the main anthocyanins of some local cultivars, their chemical characterization and their ampelographic description were one of the main achievements of this work. CONCLUSION: The use of red grapes to obtain 'saba' seems more rational for the presence of higher amounts of antioxidant substances. Ancellotta showed several factors interesting for 'saba' production, such as the very high anthocyanin content, including anthocyanin antioxidants. A more detailed investigation on 'agresto' technology is required.

Prediction of compositional and sensory characteristics using RGB digital images and multivariate calibration techniques.

In the present paper, the possibility to use the information contained in RGB digital images to gain a fast and inexpensive quantification of colour-related properties of food is explored. To this aim, we present an approach which consists, as first step, in condensing the colour related information contained in RGB digital images of the analysed samples in one-dimensional signals, named colourgrams. These signals are then used as descriptor variables in multivariate calibration models. The feasibility of this approach has been tested using as a benchmark a series of samples of pesto sauce, whose RGB images have been used to predict both visual attributes defined by a panel test and the content of various pigments (chlorophylls a and b, pheophytins a and b, ß-carotene and lutein). The possibility to predict correctly the values of some of the studied parameters suggests the feasibility of this approach for fast monitoring of the main aspect-related properties of a food matrix. The values of the squared correlation coefficient computed in prediction on a test set (R(Pred)(2)) for green and yellow hues were greater than 0.75, while R(Pred)(2) values greater than 0.85 were obtained for the prediction of total chlorophylls content and of chlorophylls/pheophytins ratio. The great flexibility of this blind analysis method for the quantitative evaluation of colour related features of matrices with an inhomogeneous aspect suggests that it is possible to implement automated, objective, and transferable systems for fast monitoring of raw materials, different stages of the manufacture and end products, not necessarily for the food industry only.

Evaluation of the combined effects of enzymatic treatment and aging on lees on the aroma of wine from Bombino bianco grapes.

In this study, two different doses of commercial beta-glucanase enzyme preparation were tested to verify their effect on wines aged on lees. These wines were compared with two samples with no enzymatic treatment. The former was aged on lees (control), and the latter was readily filtered off from the yeast cell biomass (standard). Analysis of variance (one-way ANOVA), the Tukey test, and principal component analysis (PCA) were applied to all of the samples, which were analyzed for aroma composition, along with galacturonic acid, total acidity, pH, and color. Results showed a large number of statistically significant differences among samples. In general, wines treated with beta-glucanase were characterized by higher concentration of many volatile compounds. The presence of lees and even more the exogenous enzymatic action enhanced almost all volatile compounds. Besides the high presence of ethyl esters, it is worth mentioning the behavior of hexanol and trans-3-hexenol, which are strongly enhanced by the presence of lees and by enzymatic treatments.

Determination of furanic compounds in traditional balsamic vinegars by ion-exclusion liquid chromatography and diode-array detection.

A method for the determination of furanic compounds in traditional balsamic vinegars is proposed. It is based on ion-exclusion chromatographic separation and diode-array detection of furans through an isocratic elution with 0.01 N phosphoric acid and 16% acetonitrile. Preliminary trials on standard compounds stability in heat-acidic conditions are also performed. In all the 19 samples analyzed, 2-furoic acid, 5 HMF, and furfural are found. No sample contains 4-hydroxy-2,5-dimethyl-3-(2H)-furanone (DHMF); 2-acetylfuran; or furfuryl alcohol. Three unknown compounds are also detected. The last eluting of these compounds is identified as 5-acethoxymethylfurfural, and, notwithstanding a partial hydrolysis in our chromatographic conditions, its quantitation can be carried out.