A Novel Method for the Quantification of White Wine Mannoproteins by a Competitive Indirect Enzyme-Linked Lectin Sorbent Assay (CI-ELLSA)

Mannoproteins (MPs) are cell wall proteoglycans released in wine by yeast during fermentation and ageing on lees, a procedure used for the production of several wines to enrich them in these components with consequences from both a technological and sensory point of view. Given the significance that wine MPs have for wine quality, winemakers would welcome a simple and accurate method for their quantification, as this would allow them to have a better control of this aspect at different winemaking stages. This study develops and validates a novel, simple and accurate method for MPs quantification in white wines based on a competitive indirect enzyme-linked lectin sorbent assay (CI-ELLSA), using the highly mannosylated yeast invertase as the standard. The method utilizes the lectin concanavalin A (ConA) as the immobilized ligand for MPs, and peroxidase, an enzyme rich in mannose, as the competitor for ConA. After addition of the peroxidase substrate, the intensity of the signal produced by the activity of this enzyme (absorbance at 450 nm) is inversely proportional to the amount of mannosylated proteins in the sample. Results have been validated on several wine styles including still, sparkling and sweet wines

Potentiality of protein fractions from the house cricket (Acheta domesticus) and yellow mealworm (Tenebrio molitor) for pasta formulation

House cricket (Acheta domesticus; AD) and yellow mealworm (Tenebrio molitor; TM) are two promising insect species for possible novel food applications. In this research the insect protein fractions were extracted, characterised, and used in the manufacturing of pasta by replacing semolina with 14% of powdered proteins. Pasta samples were then analysed to evaluate technological quality aspects. Results showed that insect protein inclusion resulted in a darker (L* value: 76.7, 53.4, 59.9 for control, AD and TM, respectively) and firmer (12.4, 13.7, 13.8 N: control, AD and TM, respectively) AD and TM pasta, and a higher water absorption index for AD (148, 178, 150%: control, AD and TM, respectively). In conclusion, both extracts offer interesting opportunity for pasta formulations, possibly leading to an improved protein content and quality. From an industrial perspective, the present study demonstrated that the tested edible insects can provide protein extracts for the possible fortification of pasta with high-quality protein and technological traits, thus representing an ingredient with interesting potential for several food applications

Consumer acceptability of sugar-reduced bran-rich biscuits

Biscuits are a popular category of cereal-based food with a relatively high energy density. Biscuits main component usually are wheat, sucrose and fat. Despite the lack of a general consensus from the scientific community, consumers opinion and influential diet guidelines indicate that reducing food sugar content might be beneficial to public health. Products rich in fibres and containing sweeteners with reduced caloric load might represent the right balance among nutritional value and acceptability. The present work compares the acceptability of four biscuits with high content of roasted wheat bran (14%), baked with brown cane sugar; maltitol; maltitol and stevia; brown cane sugar and stevia. The relative amount of the different sweeteners has been computed based on relative sweetness value (Edwards et al., 2016) with little modifications. Young consumers (n = 425; 48% male, 52% female; average age 23 years) rated the products for acceptability of appearance, friability, sweetness, salty and bitter taste using a 10-point hedonic scale. Biscuits were further assessed by SEM image and texture analyses in order to compare these results with those of the consumer test. For overall acceptability, biscuits with brown cane sugar were significantly more liked than their reformulated counterpart; the biscuits containing stevia and maltitol and only maltitol where not significantly different whereas the product with lowest caloric content, stevia and maltitol, scored the lowest appreciation. Variance in the overall acceptability was predominantly driven by sweet taste and friability. No major changes were found on overall acceptability based on consumer habits. Differences in the product texture were evidenced in the texture and image analyses. In conclusion the product better conjugating overall acceptability and reduced sucrose consumption was the biscuit containing maltitol as sweetener

Evaluation of the phenolic profile and immunoreactivity of Mal d 3 allergen in ancient apple cultivars from Italy

BACKGROUND: Since the second half of the 20th century, the cultivation of ancient and local apple cultivars has almost disappeared from orchards in Italy. Some of these ancient apple cultivars often possess high nutraceutical values and display lower allergenicity than the modern ones, supporting the so-called \u2018green revolution\u2019 theory. RESULTS: In this study, the phenolic composition and the antioxidant activity of five ancient apple cultivars (\u2018Belfiore\u2019, \u2018Pomella Genovese\u2019, \u2018Gravenstein\u2019, \u2018Bella del Bosco\u2019, and \u2018Piatlin\u2019) were compared with a \u2018Golden Delicious\u2019 commercial cultivar. Additionally, apples were tested for their potential allergenicity by detecting the presence of Mal d 3, a non-specific lipid transfer protein that represents the main apples' allergen. All apples came from northern Italy (Trentino Region) and were organically produced. Results showed that, for all cultivars, the skins contained more polyphenols than the pulps. \u2018Bella del Bosco\u2019 had the highest amount of polyphenols and antioxidant activity, whereas \u2018Piatlin\u2019 had the lowest phenolic content. All ancient cultivars presented a higher amount of pulp phenolic compounds than \u2018Golden Delicious\u2019. Immunoblotting techniques showed that \u2018Bella del Bosco\u2019 and \u2018Piatlin\u2019 had very low quantities of Mal d 3 allergen; hence, they can be considered hypoallergenic cultivars. CONCLUSIONS: The preservation of ancient apple cultivars would be of great importance, not only to maintain the biodiversity but also for their nutritional properties. The hypoallergenic activity of some of these cultivars could be of interest also for the preparation of different apple-based products

Different expression of Pp-LTP1 and accumulation of Pru p 3 in fruits of two Prunus persica L. Batsch genotypes

The full-length cDNAs of Pp-LTP1 and Pp-LTP2, two members of the lipid transfer protein (LTP) multigene family in peach (Prunus persica L. Batsch), have been isolated along with the proximal promoter and the complete genomic sequence of Pp-LTP1. As observed in other plant species, Pp-LTP1 is organized in two exons and, according to the deduced amino acid sequence of the secreted protein, it encodes the 9 kDa allergenic protein Pru p 3. Pp-LTP1 transcripts and Pru p 3 protein markedly accumulate in epicarp of ripe fruit in all of the peach and nectarine varieties examined (including 'Royal Gem') with the exception of 'Rita Star' that shows weak specific mRNA hybridization signal and no Pru p 3 accumulation. SDS-PAGE clearly displays a different banding pattern in correspondence of 9 kDa between 'Rita Star' and 'Royal Gem'. In immunoblotting analysis, performed using sera of eight LTP pos+ patients, a strong band is present when using 'Royal Gem' epicarp extract but not in the case of 'Rita Star'. According to these data, 'Rita Star' appears an interesting model to better elucidate the role of LTP in fruit development and allergenic reactions

Evolution of the allergenic potential in peach and nectarine fruits during ripening

According to recent epidemiological studies, in many countries food allergies increased strongly during recent decades. Allergies to fruits represent also an emerging problem and studies should be addressed to identify allergens, evaluate the allergenic potential of different species and varieties and, possibly, produce hypoallergenic fruits. In peach, the major allergen has been identified as a Lipid Transfer Protein (LTP) and in the present research the evolution of the allergenic potential of different peach and nectarine varieties has been monitored throughout ripening and in relation to postharvest treatments. Fruits of peach cv. \u2018Royal Gemm\u2019, \u2018Zorzi\u2019, of nectarine cv. \u2018Rita Star\u2019, \u2018Early Giant\u2019 and \u2018Maria Dorata\u2019, and of flat type (Platicarpa) were harvested in correspondence of commercial ripeness and allowed to ripen at room temperature or stored at 4\ub0C for 3 weeks. Northern blot analyses were carried out on total RNA extracted from epicarp and mesocarp to study Pp-LTP1 gene expression. Immunological studies were performed by means of a polyclonal antibody raised against the purified protein. Expression analysis showed that Pp-LTP1 transcripts accumulated only in the epicarp. With the exception of cv. \u2018Rita Star\u2019 the strongest accumulations have been detected in epicarp of all varieties at harvest. With the exception of Platicarpa, a decreasing trend of expression was observed in fruits kept in air and at 4\ub0C. Western blots revealed the presence of LTP only in epicarp of all studied varieties, but not in \u2018Rita Star\u2019, and showed that the protein markedly increased in full ripe fruits maintained in air. This might indicate the presence of a lag between gene transcription and accumulation of secreted functional LTP. According to these results, cv. \u2018Rita Star\u2019 appears to be a variety with a reduced allergenic potential

Old apple (malus domestica L. Borkh) varieties with hypoallergenic properties: an integrated approach for studying apple allergenicity

Freshly consumed apples (Malus domestica L. Borkh) can cause allergic reactions because of the presence of four classes of allergens. Knowledge of the genetic factors affecting the allergenic potential of apples would provide important information for the selection of hypoallergenic genotypes, which can be combined with the adoption of new agronomical practices to produce fruits with a reduced amount of allergens. In the present research, a multiple analytical approach was adopted to characterize the allergenic potential of 24 apple varieties released at different ages (pre- and post-green revolution). A specific workflow was set up including protein quantification by means of polyclonal antibodies, immunological analyses with sera of allergic subjects, enzymatic assays, clinical assessments on allergic patients, and gene expression assays on fruit samples. Taken as a whole, the results indicate that most of the less allergenic genotypes were found among those deriving from selection processes carried out prior to the so-called "green revolution"

Alla ricerca della mela ipoallergenica: strategie e prospettive future

Lo studio delle allergie sta assumendo sempre maggiore importanza nell\u2019ambito della ricerca agroalimentare. La mela \ue8 uno dei frutti che \ue8 pi\uf9 frequentemente coinvolto in reazioni allergiche. Per questo motivo, numerosi progetti nazionali e internazionali (es. progetti europei SAFE e ISAFRUIT), sono stati dedicati allo studio delle allergie a questo frutto, chiarendone alcuni aspetti sia dal punto di vista clinico-allergologico, sia dal punto di vista biochimico-molecolare. Tali progetti hanno contribuito alla formazione di una prima rete di ricerca nazionale e internazionale su questo importante argomento. Nell\u2019ambito di queste iniziative, si colloca il progetto AGER-Melo che sta affrontando alcuni aspetti critici dell\u2019allergia alla mela, nell\u2019ottica del miglioramento della qualit\ue0 e della salubrit\ue0 del frutto, coinvolgendo competenze mediche, biochimiche, genetico-molecolari e agro-biotecnologiche. Nel melo sono state identificate 4 famiglie di principali allergeni: Mal d 1, 2, 3 e 4, ognuna composta da numerose isoforme che aumentano la complessit\ue0 delle ricerche. Nell\u2019AGER-Melo sono state previste diverse linee di ricerca allo scopo di valutare il potenziale allergenico della mela e i fattori endogeni ed esogeni che lo determinano. Tali valutazioni sono attualmente in corso mediante l\u2019impiego di diverse tecniche quali l\u2019utilizzo di sieri di pazienti allergici, di anticorpi policlonali specifici per ogni famiglia di allergeni, di analisi della espressione di ogni singolo allergene e dell\u2019intero trascrittoma dei genotipi pi\uf9 promettenti. L\u2019identificazione dei determinanti dell\u2019allergenicit\ue0 della mela permetter\ue0 di ottenere variet\ue0 ipoallergeniche anche mediante la progettazione di programmi di miglioramento genetico dedicati a questo scopo con l\u2019obiettivo finale di consentire anche a persone allergiche di consumare questo frutto particolarmente noto anche per il suo valore nutrizionale. Questo studio \ue8 finanziato dal Progetto AGER-Melo, grant n\ub0 2010-2119