Composition of phenolics and volatiles in strawberry cultivars and influence of preharvest hexanal treatment on their profiles

Biochemical changes of quality-determining components were evaluated in strawberry fruit subjected to preharvest spray treatments using a hexanal-containing formulation that is known to enhance shelf life and quality of fruits. Phenolic compounds and volatiles of fruits of four strawberry cultivars (Mira, Jewel, Kent, and St. Pierre) grown in southern Ontario were characterized by HPLC-MS and solid phase micro extraction (SPME) analysis. Qualitative and quantitative profiles of phenolic compounds varied among the cultivars. In all the cultivars, anthocyanins constituted the most prominent class of phenolic compounds. Volatile profiles of strawberry homogenate differed among the cultivars. Changes in phenolics and volatiles composition were determined in fruits of Mira and Jewel after spraying with a hexanal-containing formulation at weekly intervals. In Jewel, preharvest hexanal spraying altered the profiles of polyphenolic components, while minimal changes were noticed in Mira. Interestingly, very few differences were identified in ester profiles of treated and untreated Mira. In general, hexanal spray application resulted in a decrease in the abundance of several volatile components including esters, ketones, and lactones in treated Jewel compared with the control. The results suggest that cultivar-specific quality changes may result from a preharvest application of hexanal formulations, which may also imply different patterns of metabolite channeling and delay of fruit ripening processes

Identification and characterization of genes involved in the fruit color development of european plum

European plum fruit (Prunus domestica) are normally blue-black to dark purple. However, some genotypes remain green/yellow after ripening. We hypothesized that in such genotypes anthocyanin biosynthesis is genetically disturbed. To examine this hypothesis, six european plum genotypes with diverse fruit colors were investigated for the expression pattern of several anthocyanin biosynthetic genes (ABGs)—e.g., phenylalanine ammonia-lyase, chalcone synthase (CHS), dihydroflavonol 4-reductase (DFR), anthocyanin synthase (ANS), and UDP-glucose:flavonoid 3-O-glucosyltransferase 1 and 2 (UFGT 1 and 2). Expression profiles indicated that ABGs, especially Pd-CHS and UFGT 2, were significantly downregulated in the green/yellow fruit compared with the dark-purple fruit. Furthermore, the quantification of total polyphenols and individual flavonoid compounds showed substantial differences between the off-colored and the purple genotype. To further examine the contribution of each of the ABGs in color development, the open reading frame (ORP) of Pd-CHS, Pd-DFR, Pd-ANS, and Pd-UFGT 2 was ectopically expressed in tobacco (Nicotiana tabacum). The characterization of transgenic plants showed that the petals of plants expressing Pd-CHS were darker in color and had higher anthocyanin content than control or even other transgenic types, suggesting the significant contribution of CHS in determining anthocyanin production levels and hence fruit coloration. The results of this study provides better understanding of color development in european plum, which can be rewarding in developing european plum cultivars with desired colors through classical or modern breeding tools

The Biochemical and Cellular Basis for Nutraceutical Strategies to Attenuate Neurodegeneration in Parkinson’s Disease

Future therapeutic intervention that could effectively decelerate the rate of degeneration within the substantia nigra pars compacta (SNc) could add years of mobility and reduce morbidity associated with Parkinson’s disease (PD). Neurodegenerative decline associated with PD is distinguished by extensive damage to SNc dopaminergic (DAergic) neurons and decay of the striatal tract. While genetic mutations or environmental toxins can precipitate pathology, progressive degenerative succession involves a gradual decline in DA neurotransmission/synaptic uptake, impaired oxidative glucose consumption, a rise in striatal lactate and chronic inflammation. Nutraceuticals play a fundamental role in energy metabolism and signaling transduction pathways that control neurotransmission and inflammation. However, the use of nutritional supplements to slow the progression of PD has met with considerable challenge and has thus far proven unsuccessful. This review re-examines precipitating factors and insults involved in PD and how nutraceuticals can affect each of these biological targets. Discussed are disease dynamics (Sections 1 and 2) and natural substances, vitamins and minerals that could impact disease processes (Section 3). Topics include nutritional influences on α-synuclein aggregation, ubiquitin proteasome function, mTOR signaling/lysosomal-autophagy, energy failure, faulty catecholamine trafficking, DA oxidation, synthesis of toxic DA-quinones, o-semiquinones, benzothiazolines, hyperhomocyseinemia, methylation, inflammation and irreversible oxidation of neuromelanin. In summary, it is clear that future research will be required to consider the multi-faceted nature of this disease and re-examine how and why the use of nutritional multi-vitamin-mineral and plant-based combinations could be used to slow the progression of PD, if possible

Physical and metabolic alterations in "Prata Anã" banana induced by mechanical damage at room temperature

Bananas respond at the physical and physiological level to mechanical damage. Mechanical injuries cause alterations in color and flavor, tissue softening, faster ripening, increased weight loss, increased invasion of microorganisms, and higher enzyme activity in the affected area. The purpose of this study was to verify the physical and metabolic alterations in 'Prata Anã' bananas induced by mechanical stress at room temperature. The experiment was conducted in a completely randomized, split-plot in time design, consisting of one control and four mechanical injury types: cutting, abrasion, impact and compression, sampled over time. The percentage of accumulated and daily fresh weight loss, electrolyte leakage from the injured peel region, total soluble sugar and starch contents and enzyme activity of polyphenoloxidase and peroxidase were measured. The damage caused by cutting and abrasion resulted in the highest percentage of fresh weight loss. All types of mechanical damage increased electrolyte leakage during the evaluation period, in comparison with the control. The impact damage anticipated the ripening, besides affecting the conversion of starch into total soluble sugars in the pulp. By impact and abrasion injuries, the polyphenoloxidase and peroxidase activity in the peel was increased by up to 231% and 90%, and 618% and 956%, respectively, compared to the control.Bananas apresentam respostas físicas e fisiológicas ao dano mecânico. As injúrias mecânicas causam alterações na cor e sabor, amaciamento dos tecidos, amadurecimento mais rápido, aumento na perda de peso, aumento no ataque e invasão de microorganismos e maior atividade enzimática na área afetada. Verificaramse alterações físicas e metabólicas induzidas por estresse mecânico em bananas 'Prata Anã' mantidas em temperatura ambiente. Foi utilizado o esquema em parcelas subdivididas no tempo, constituído de testemunha e quatro fontes de dano mecânico: corte, abrasão, impacto e compressão, com amostragens ao longo do tempo, no delineamento inteiramente casualizado. As porcentagens de perda de massa fresca acumulada e diária, o extravasamento de eletrólitos da região danificada da casca, os teores de açúcares solúveis totais e amido e a atividade das enzimas polifenoloxidase e peroxidase foram avaliadas. Os danos por corte e abrasão promoveram maior porcentagem de perda de massa fresca. Todos os tipos de dano mecânico aumentaram extravasamento de eletrólitos em relação à testemunha ao longo do período de avaliação. O dano por impacto antecipou o amadurecimento, além de prejudicar a conversão de amido em açúcares solúveis totais na polpa. As injúrias por impacto e abrasão aumentaram a atividade das enzimas polifenoloxidase e peroxidase na casca em até 231 e 90%, e 618 e 957%, respectivamente, em relação ao controle