Affinity and selectivity of plant proteins for red wine components relevant to color and aroma traits

The effects of fining with various plant proteins were assessed on Aglianico red wine, using both the young wine and wine aged for twelve and twenty-four months, and including wine unfined or fined with gelatin as controls. Color traits and fining efficiency were considered, along with the content of various types of phenolics and of aroma-related compounds of either varietal or fermentative origin. All agents had comparable fining efficiency, although with distinct kinetics, and had similar effects on wine color. Individual plant proteins and enzymatic hydrolyzates differed in their ability to interact with some anthocyanins, with specific proanthocyanidins complexes, and with some aroma components of fermentative origin. Changes in varietal aroma components upon fining were very limited or absent. Effects of all the fining agents tested in this study on the anthocyanidin components were most noticeable in young red wine, and decreased markedly with increasing wine ageing

Grape skin phenolics as inhibitors of mammalian α-glucosidase and α-amylase – effect of food matrix and processing on efficacy

Inhibition of mammalian α-amylase and α-glucosidase was studied for white grape skin samples recovered from wineries and found to be higher than that of the drug acarbose

Probiotics action on gliadin sequences relevant to gluten sensitivity

The Celiac disease in genetically predisposed individuals is mainly induced by specific repetitive sequences in gliadins (PQPYP). This autoimmune disease stems from the interaction between toxic sequences and lamina propria cells, that is relevant also to other forms of gluten sensitivity. Specific endo-esoprolinase were isolated from lactic acid bacteria, suggesting possible practical applications. The ability of some probiotics at removing "toxic" celiac sequences was investigated, at first by assessing the presence and level of endo- and eso-prolinase activity in some of the most popular probiotic bacteria. Significant activities were detected in Lactobacillus and Bifidum species, as well as in the probiotic Escherichia coli Niessle 1917. On the basis of prolinase data, we investigated by mass spectroscopy the removal of "toxic" sequences in gliadin. A complete disappearance of these sequences was observed only with Escherichia coli Niessle 1917. Among the Bifidus and Lactobacillus species, only B. bifidum MIMBb23SG and L. acidophilus LA5 showed a significant decrease in the "toxic" sequences. All together, this study suggests a potential use of lactic bacteria to lower gluten response in sensitive individuals, including celiacs and gluten-sensitive

Characterization of Whole Grain Pasta: Integrating Physical, Chemical, Molecular, and Instrumental Sensory Approaches

The consumption of whole-grain foodincluding pastahas been increasing steadily. In the case of whole-grain pasta, given the many different producers, it seems important to have some objective parameters to define its overall quality. In this study, commercial whole-grain pasta samples representative of the Italian market have been characterized from both molecular and electronic-senses (electronic nose and electronic tongue) standpoint in order to provide a survey of the properties of different commercial samples. Only 1 pasta product showed very low levels of heat damage markers (furosine and pyrraline), suggesting that this sample underwent to low temperature dry treatment. In all samples, the furosine content was directly correlated to protein structural indices, since protein structure compactness increased with increasing levels of heat damage markers. Electronic senses were able to discriminate among pasta samples according to the intensity of heat treatment during the drying step. Pasta sample with low furosine content was discriminated by umami taste and by sensors responding to aliphatic and inorganic compounds. Data obtained with this multidisciplinary approach are meant to provide hints for identifying useful indices for pasta quality. Practical ApplicationAs observed for semolina pasta, objective parameters based on heat-damage were best suited to define the overall quality of wholegrain pasta, almost independently of compositional differences among commercial samples. Drying treatments of different intensity also had an impact on instrumental sensory traits that may provide a reliable alternative to analytical determination of chemical markers of heat damage in all cases where there is a need for avoiding time-consuming procedures

Pollo brianzolo : performance e reattività

Nell\u2019ultimo decennio, a seguito di una forte industrializzazione dell\u2019allevamento avicolo, sono emerse due questioni fondamentali: da un punto di vista etico-scientifico, la necessit\ue0 di salvaguardare la biodiversit\ue0; da un punto di vista prettamente commerciale; la richiesta da parte di un consumatore pi\uf9 attento e cosciente, di produrre carne e uova provenienti da allevamenti alternativi, pi\uf9 rispettosi dell\u2019ambiente e del benessere animale. Il pollo Brianzolo \ue8 un esempio di recupero della tradizione rurale e di un prodotto tipico. Lo scopo del presente lavoro \ue8 stato quello di caratterizzare l\u2019ibrido \u201cPollo Brianzolo\u201d dal punto di vista delle caratteristiche fenotipiche, della reattivit\ue0 e degli aspetti produttivi. Con cadenza settimanale sono stati registrati i parametri relativi alle caratteristiche quali-quantitative delle uova incubate e, in seguito alla schiusa, sono stati raccolti i dati relativi alle performance di crescita fino all\u2019et\ue0 di 6 mesi. All\u2019et\ue0 di 4 mesi, 145 animali sono stati valutati fenotipicamente per fissare lo standard di razza e su un campione di 93 soggetti scelti random, \ue8 stato effettuato il test di immobilit\ue0 tonica. I risultati della selezione fenotipica hanno consentito di fissare i caratteri somatici quali, ad esempio, forma della cresta e colore della livrea, che saranno l\u2019obiettivo della selezione. I risultati di questo lavoro, pur preliminari, sembrano mettere in evidenza le caratteristiche di buona rusticit\ue0, accrescimento lento (peso medio a 6 mesi= 2350 g; IMG=13,5 g/d) e di una reattivit\ue0 che mantiene le caratteristiche ancestrali del pollo Brianzolo. La media del numero di induzioni durante il test di immobilit\ue0 tonica \ue8 di 1,25, mentre la durata media del test \ue8 di 98,19 sec. Questi risultati preliminari verranno sottoposti ad ulteriore validazione attraverso lo studio delle generazioni successive. Accanto alle valutazioni sui parametri produttivi e riproduttivi, la reattivit\ue0 e le caratteristiche fenotipiche verranno valutate le caratteristiche qualitative della carne.Performance and reactivity in Brianzolo chicken. Unconventional rearing systems for poultry meat production greatly increased due to consumers interest in healthier and more natural food. The poor adaptability of commercial hybrid strains selected for intensive production systems and fast growing rate lead to the development of researches dealing with breed suitability for alternative productions. Brianzolo is an example of Italian chicken breed for unconventional system. The aim of this study was to characterize the hybrid \u201cBrianzolo\u201d for fenotipic caracteristics, reactivity and performance. Hatching eggs qualitative and quantitative characteristics parameters were recorded on a weekly basis and to growth performance data were collected 1 day to 6 months of age. To define the breed standard 145 animals were phenotypically tested at the age of 4 months. Tonic Immobility test was carried out on 93 subjects randomly chosen. Results of the phenotypic selection made it possible to standardize some characteristics such as, comb size and plumage colour, that will be selection objective to standardize birds morphology.The results of this study, although preliminary, showed productive performance typical for slow growing to a rural breeds adapted to alternative production systems (average weight at 6 months = 2350 g; IMG = 13.5 g / d). Regarding reactivity in this hybrid the conservation of ancestral characteristics such as man fear was evaluated through TI test for reactivity. The mean number of attempt to induce immobility was 1,25, while the mean duration was 98,19 sec. Brianpollo is a research project funded by Regione Lombardia (Italy) aimed to standardize and valorize Brianzolo chicken, a traditional Lombardy breed for non-conventional rearing systems (Ferrante et al., 2009)

Purified sakacin A shows a dual mechanism of action against Listeria spp: proton motive force dissipation and cell wall breakdown

Sakacin A was purified to homogeneity through simple chromatographic procedures from cultures of Lactobacillus sakei DSMZ 6333 grown on a low-cost medium. The highly purified protein dissipated both transmembrane potential (\u394\u3a8) and transmembrane pH gradient (\u394pH) in Listeria cells in a very intense, rapid, and energy-dependent fashion. On a slower timescale, purified sakacin A also showed a lytic activity toward isolated cell walls of Listeria. Mass spectrometry was used to analyze the products of sakacin A action on cell walls, evidencing that sakacin A acts on various types of bonds within peptoglycans

Whey protein mouth drying influenced by thermal denaturation

Whey proteins are becoming an increasingly popular functional food ingredient. There are, however, sensory properties associated with whey protein beverages that may hinder the consumption of quantities sufficient to gain the desired nutritional benefits. One such property is mouth drying. The influence of protein structure on the mouthfeel properties of milk proteins has been previously reported. This paper investigates the effect of thermal denaturation of whey proteins on physicochemical properties (viscosity, particle size, zeta-potential, pH), and relates this to the observed sensory properties measured by qualitative descriptive analysis and sequential profiling. Mouthcoating, drying and chalky attributes built up over repeated consumption, with higher intensities for samples subjected to longer heating times (p < 0.05). Viscosity, pH, and zeta-potential were found to be similar for all samples, however particle size increased with longer heating times. As the pH of all samples was close to neutral, this implies that neither the precipitation of whey proteins at low pH, nor their acidity, as reported in previous literature, can be the drying mechanisms in this case. The increase in mouth drying with increased heating time suggests that protein denaturation is a contributing factor and a possible mucoadhesive mechanism is discussed

Molecular Aspects of the Functional Activities of Pigmented Grains

I cereali colorati sono ricche fonti di antociani con attivit\ue0 antiossidante, ed hanno un grande potenziale non solo come coloranti alimentari ma anche come ingredienti alimentari in grado di esercitare effetti benefici per la salute. La quantificazione del tenore di antocianine e polifenoli nei cereali \ue8 cruciale per valutare in modo appropriato i loro benefici nutrizionali e per consentire la loro applicazione come materie prime alimentari con propriet\ue0 funzionali. Il nostro obiettivo era studiare le attivit\ue0 anti-infiammatorie di estratti ricchi di antociani da diversi grani pigmentati utilizzando cellule Caco-2 transfettate con un vettore pNiFty2-Luc, e di analizzare la capacit\ue0 di questi estratti nell\u2019inibire l\u2019attivit\ue0 dell'alfa-amilasi pancreatica e delle alfa-glucosidasi intestinali

Advances in the combined application of enzymatic and physical treatments for reducing food allergenicity

Enzymatic hydrolysis of allergenic food proteins (betalactoglobulin, ovalbumin) was carried out during treatment at different combinations of time, pressure and temperature, with the aim of hydrolyzing the protein conformers transiently formed in the course of physical treatment in conditions where no irreversible modification of the target protein occurs. The amount of residual intact betalactoglobulin after 10 min at 600 MPa in the presence of trypsin or chymotrypsin was found to decrease markedly with increasing temperature (30-44\ub0C). The temperature sensitivity of the enzymatic hydrolysis of ovalbumin during similar treatments was much less pronounced than that of betalactoglobulin. The effects of temperature on the accessibility of betalactoglobulin conformers to proteases were studied at higher temperatures (55-65\ub0C), and indicated that complete hydrolysis of betalactoglobulin cannot be achieved in a short time in the absence of a pressure treatment. None of the hydrolysis products of either protein was immunoreactive in Western-blot immunoassays