Bambusa vulgaris starch: Characterization and technological properties.

The starch industry has grown quickly, and starch production has expanded around the world because it is a very versatile ingredient, despite limits in some foodstuffs. So, this study aimed to analyze morphology, physic and chemical characteristics of the starch extracted from three different parts (bottom, middle and top) of the young bamboo culm of B. vulgaris (SB, SM, and ST, respectively). The obtained data were evaluated by analysis of variance and Scott-Knot test (p < 0.05), and no significant difference was observed between SB, SM and ST samples. The starches presented yellowish coloration (L* > 88, a* > -0.2, and b* > 9), and SEM images showed compound granules with polyhedral shapes and average diameter of 6.55 µm; apparent amylose content of 37.45%, wherein SB and SM showed characteristics of resistant starch type 2, whereas ST was more similar to normal starch. Amylopectin presented high proportion of chains with DP 13-24 and lower proportion of long chains, corroborating with A-type crystalline pattern. The absence of a shoulder in the branch chain length distribution, suggest a perfect crystalline structure, similar to starches from D. asper and B. tuldoides. DSC shows gelatinization temperatures higher than 80 °C, lower transition temperatures and the percentage of retrogradation above 44%. The results are promising to obtain slow digesting starches, although it is necessary to evaluate the starch from other bamboo species, which may have different characteristics.

Characterization of young bamboo culm starch from Dendrocalamus asper.

The search for new and natural ingredients has been stimulated by the food and non-food industries, and the fresh young bamboo culm of Dendrocalamus asper emerges as promising for industrial production due to its composition with >10% of starch. So, this study aimed to characterize starch, extracted in aqueous solution, from three different parts (bottom, middle and top) of the young bamboo culm of D. asper (SB, SM and ST, respectively). Morphological and physicochemical characteristics of the young bamboo culm starches were evaluated, besides thermal properties, and the obtained data were evaluated by ANOVA and Scott-Knot test (p < 0.05). The starches presented pale yellow coloration, with high luminosity (L*  > 89), and lower index in the red region. SEM images showed compound granules, which under polarized light exhibit a Maltese cross. The starches presented polyhedral shape and small size with an average diameter of 5.4 µm. All the samples presented low moisture (7.0 g/100 g), protein (2.0 g/100 g), lipid (0.3 g/100 g) and ash (1.0 g/100 g) contents. ST and SB showed apparent amylose content similar to starches from cereals and isolated from bamboo seeds. This agress to molecular size distribution of starch chains, since the SB, SM and ST presented amylopectin levels higher than those of amylose, as well as normal starches. The chain length of amylopectin presented the main peak at DP 12-13 and the second on at DP 43, similar to cereals like wheat, rice and barley. Its chain has higher proportion of short chains, which corroborates with the A-type polymorph presented. Concerning about thermal properties, all the samples presented high gelatinization temperature (>78 °C) and low enthalpies values (<6.35 J·g-1), which indicates the greater molecular organization. The gelatinization temperatures of gelatinized starches were lower than the native ones. The physicochemical and thermal characteristics of the obtained starches corroborate with the success of the extraction, which keep the starch granule native, and were similar to those of other starches already used in food and non-food products.

Structural, thermal, and morphological characteristics of cassava amylodextrins.

BACKGROUND: Amylodextrins from cassava starch were obtained by acid hydrolysis, and their structural, thermal and morphological characteristics were evaluated and compared to those from potato and corn amylodextrins. RESULTS: Cassava starch was the most susceptible to hydrolysis due to imperfections in its crystalline structure. The crystalline patterns of amylodextrins remained unchanged, and crystallinity and peak temperature increased with hydrolysis time, whereas thermal degradation temperature decreased, independent of treatment time and starch source. Cassava amylodextrins had similar structural and morphological characteristics to those from corn amylodextrins due to their A-type crystalline arrangements. A-amylodextrins were structurally and thermally more stable than potato amylodextrins (B-type). Starch nanocrystals (SNC) were observed by transmission electron microscopy from the third day of hydrolysis in cassava amylodextrins, whereas potato and corn amylodextrins displayed SNC only on the fifth day. A-SNC displayed platelet shapes, whereas B-SNC were rounded. The SNC shape was related to the packing form and geometry of unit cells of allomorphs A and B. CONCLUSION: Microstructures (agglomerated crystalline particles) and nanostructures (double helix organization) were observed for amylodextrins. Cassava starch was shown to be a promising material for SNC production, since it requires less hydrolysis time to obtaining more stable crystals. © 2017 Society of Chemical Industry.

Clinical rearfoot and knee static alignment measurements are not associated with patellofemoral pain syndrome / Medidas clínicas estáticas do retropé e joelho não estão associadas à síndrome da dor patelofemoral

The aim of the present study was to investigate the association between the patellofemoral pain syndrome and the clinical static measurements: the rearfoot and the Q angles. The design was a cross-sectional, observational, case-control study. We evaluated 77 adults (both genders), 30 participants with patellofemoral pain syndrome, and 47 controls. We measured the rearfoot and Q angles by photogrammetry. Independent t-tests were used to compare outcome continuous measures between groups. Outcome continuous data were also transformed into categorical clinical classifications, in order to verify their statistical association with the dysfunction, and χ2 tests for multiple responses were used. There were no differences between groups for rearfoot angle [mean differences: 0.2º (95%CI -1.4-1.8)] and Q angle [mean differences: -0.3º (95%CI -3.0-2.4). No associations were found between increased rearfoot valgus [Odds Ratio: 1.29 (95%CI 0.51-3.25)], as well as increased Q angle [Odds Ratio: 0.77 (95%CI 0.31-1.93)] and the patellofemoral pain syndrome occurrence. Although widely used in clinical practice and theoretically thought, it cannot be affirmed that increased rearfoot valgus and increased Q angle, when statically measured in relaxed stance, are associated with patellofemoral pain syndrome (PFPS). These measures may have limited applicability in screening of the PFPS development.

O objetivo deste estudo foi investigar se existe associação entre a síndrome da dor patelofemoral e as medidas clínicas estáticas: os ângulos do retropé e Q. Foi realizado um estudo observacional, transversal, caso-controle, no qual foram avaliados 77 adultos (ambos os sexos), 30 participantes com síndrome da dor patelofemoral e 47 controles. Foram medidos os ângulos do retropé e Q, por meio da fotogrametria. Testes t para amostras independentes foram usados para comparações dos resultados das variáveis contínuas entre os grupos. Os resultados das variáveis contínuas foram transformados em classificações clínicas categóricas, para verificar a associação estatística com a disfunção, e o teste do χ2 para respostas múltiplas também foi utilizado. Não houve diferença entre os grupos para o ângulo do retropé [média da diferença: 0,2º (IC95% -1,4-1,8)] e ângulo Q [média da diferença: -0,3º (IC95%-3,0-2,4). Não houve associação entre o ângulo do retropé [Odds Ratio: 1,29 (IC95% 0,51-3,25)], assim como entre o ângulo Q [Odds Ratio: 0.77 (IC95% 0,31-1,93)] e a ocorrência da síndrome da dor patelofemoral. Apesar de serem teoricamente justificadas e amplamente utilizadas na prática clínica fisioterapêutica, não pode-se afirmar que as medidas dos ângulos do retropé e Q, quando mensuradas em posição ortostática, estão associadas com a ocorrência da síndrome da dor patelofemoral. Essas medidas podem ter aplicabilidade limitada na triagem desta disfunção.