Pectin content and composition from different food waste streams.

In the present paper, 26 food waste streams were selected according to their exploitation potential and investigated in terms of pectin content. The isolated pectin, subdivided into calcium bound and alkaline extractable pectin, was fully characterized in terms of uronic acid and other sugar composition, methylation and acetylation degree. It was shown that many waste streams can be a valuable source of pectin, but also that pectin structures present a huge structural diversity, resulting in a broad range of pectin structures.

Electrospray MS and MALDI imaging show that non-specific lipid-transfer proteins (LTPs) in tomato are present as several isoforms and are concentrated in seeds.

Non-specific lipid-transfer proteins (nsLTPs) are major human allergens in many plant species, albeit their role in plant biochemistry is still undefined. They are found in many plant species, either as one or several isoforms according to the species, and usually they are found to concentrate in the outer part of the fruits. In this work, the characterization of tomato nsLTP isoforms was performed on the three main fractions of Piccadilly tomato fruit (peel, pulp and seeds) by using ultracentrifuge devices with molecular cut-off able to retain proteins with molecular weight typical of plant LTPs.

Use of peptide nucleic acids (PNAs) for genotyping by solution and surface methods.

Peptide nucleic acids (PNAs) are synthetic oligonucleotide analogues based on a pseudopeptide backbone that bind complementary DNA or RNA with high affinity and specificity. In this chapter, three PNA-based genotyping assays are described: PCR clamping, fluorescence-based recognition, and microarray platform. The first two methods are performed in solution, while the microarray method uses a solid surface.

Identification and quantification of different species in animal fibres by LC/ESI-MS analysis of keratin-derived proteolytic peptides.

In the present paper, a proteomic method for species determination in fibres has been developed. Keratin was extracted from yak, wool and cashmere fibres and digested by trypsin, providing peptide mixtures that were analyzed by liquid chromatography coupled with electrospray mass spectrometry (LC/ESI-MS) in order to identify peptidic species-specific markers able to differentiate the fibres. Several suitable peptide markers were identified and validated in different fibres of different origin and having undergone different technological treatments, showing 100% specificity and 100% selectivity.

Common wheat determination in durum wheat samples through LC/MS analysis of gluten peptides.

A method to detect the presence of common wheat in durum wheat flour samples was developed and tested. Flour samples, or ground wheat samples, were digested by pepsin and chymotrypsin, and the peptide mixture obtained was analyzed by LC/ESI-MS and LC/ESI-MS/MS, which led to the identification of two marker peptides. One peptide was coded only in the DD genome, and thus present only in common wheat; the second was present in all wheat samples (both common and durum), so it was used as marker of the total wheat content.

A PNA microarray for tomato genotyping.

The design and development of a PNA microarray designed for the simultaneous identification of several SNPs characteristic of seven different tomato varieties is described. Highly selective arginine-based monomer containing PNAs (Arg-PNAs) have been used in order to obtain very selective probes. Seven modified PNA probes were synthesised and their binding properties in solution were studied.

Affinity and selectivity of C2- and C5-substituted "chiral-box" PNA in solution and on microarrays.

Two peptide nucleic acids (PNAs) containing three adjacent modified chiral monomers (chiral box) were synthesized. The chiral monomers contained either a C2- or a C5-modified backbone, synthesized starting from D- and L-arginine, respectively (2D- and 5L-PNA). The C2-modified chiral PNA was synthesized using a submonomeric strategy to avoid epimerization during solid-phase synthesis, whereas for the C5-derivative, the monomers were first obtained and then used in solid-phase synthesis.