Çilekte aroma maddelerinin tanımlanmasında kullanılan metodların karşılaştırılması

Bu çalışmada İsrail'de ticari olarak yetiştiriciliği yapılan (Fragaria x ananassa. Duch) 3 çilek çeşidinde ("Tamar"_ "Yael" ve "Maiach") uçucu aroma kompozisyonları incelenmiştir. Aroma bileşikleri Tepe Boşluğu Katı Faz Mikro Ekstraksiyon (HS-SPME) ile sıvı-sıvı ekstraksiyon tekniği (organik çözücü: tert-butil metil eter) olmak üzere 2 farklı ekstraksiyon tekniği ve Gaz Kromatografisi Kütle Spektrometresi (GC/MS) ile belirlenmiştir. Kullanılan ekstraksiyon tekniklerinin 3 çilek çeşidinde aroma kompozisyonian üzerine etkileri incelenmiştir. Maiach çeşidi öteki çeşitlere gore ester ve furanon içerikleri bakımından daha zengin olduğu belirlenmiştir. Denemede farklı ekstraksiyon teknikleri kullanıldığında aroma profillerinde de farklılıklar olduğu dikkati çekmiştir. HS-SPME tekniğinin çok uçucu ve polar olmayan esterlerin tanımlanması için uygun olduğu sıvı ekstraksiyon tekniğinin ise daha çok polar ve uçuculuğu az olan furanon bileşiklerinin tanımlanması için uygun olduğu saptanmıştır.Three strawberry (Fragaria x ananassa. Duch.) varieties commercially grown in Israel (Tamar, Yael and Malach) were studied for their volatile compositions. Two techniques were compared: headspace solid phase micro extraction (HS-SPME) and liquid-liquid extraction (organic solvent: tert-butyl methyl ether) by gas chromatography/mass spectrometry (GC/MS). The influences of techniques on the volatile compounds were tested by comparing the volatiles determined in the 3 varieties. Malach, the most aromatic variety, accumulates high levels of furanones and esters compared to the other varieties. Differences in the aroma profiles obtained by utiliszing different techniques were noted. HS-SPME was more suitable for the determination of very volatile and non-polar esters, while liquid extraction was more appropriate for the determination of the polar and less volatile furanones

The bacterial curli system possesses a potent and selective inhibitor of amyloid formation.

Curli are extracellular functional amyloids that are assembled by enteric bacteria during biofilm formation and host colonization. An efficient secretion system and chaperone network ensures that the major curli fiber subunit, CsgA, does not form intracellular amyloid aggregates. We discovered that the periplasmic protein CsgC was a highly effective inhibitor of CsgA amyloid formation. In the absence of CsgC, CsgA formed toxic intracellular aggregates. In vitro, CsgC inhibited CsgA amyloid formation at substoichiometric concentrations and maintained CsgA in a non-β-sheet-rich conformation. Interestingly, CsgC inhibited amyloid assembly of human α-synuclein, but not Aβ42, in vitro. We identified a common D-Q-Φ-X0,1-G-K-N-ζ-E motif in CsgC client proteins that is not found in Aβ42. CsgC is therefore both an efficient and selective amyloid inhibitor. Dedicated functional amyloid inhibitors may be a key feature that distinguishes functional amyloids from disease-associated amyloids

Chromosome Xq23 is associated with lower atherogenic lipid concentrations and favorable cardiometabolic indices

Abstract Autosomal genetic analyses of blood lipids have yielded key insights for coronary heart disease (CHD). However, X chromosome genetic variation is understudied for blood lipids in large sample sizes. We now analyze genetic and blood lipid data in a high-coverage whole X chromosome sequencing study of 65,322 multi-ancestry participants and perform replication among 456,893 European participants. Common alleles on chromosome Xq23 are strongly associated with reduced total cholesterol, LDL cholesterol, and triglycerides (min P = 8.5 × 10−72), with similar effects for males and females. Chromosome Xq23 lipid-lowering alleles are associated with reduced odds for CHD among 42,545 cases and 591,247 controls (P = 1.7 × 10−4), and reduced odds for diabetes mellitus type 2 among 54,095 cases and 573,885 controls (P = 1.4 × 10−5). Although we observe an association with increased BMI, waist-to-hip ratio adjusted for BMI is reduced, bioimpedance analyses indicate increased gluteofemoral fat, and abdominal MRI analyses indicate reduced visceral adiposity. Co-localization analyses strongly correlate increased CHRDL1 gene expression, particularly in adipose tissue, with reduced concentrations of blood lipids