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Echeveria subrigida is native to Mexico and its methanol extract (ME) shows relevant biological activities for human health, including the α-glucosidase inhibitory (αGI) activity that suggests its ...

Hot water treatment (HWT) of tomato (Solanum lycopersicum L.) fruit reduces the symptoms of chilling injury (CI). The aim of this study was to identify metabolites associated with HWT-induced CI tolerance in tomato fruit cv. Imperial. Mature green tomatoes with HWT (42°C/5 min) and control were stored under chilling conditions (5°C/20 days) and then ripened (21°C/7 days). Methanol extracts from pericarp were analyzed for total phenolics (TP), antioxidant activity (AoxA), and metabolic profiling by UPLC-DAD-MS and GC-MS. After cold storage and ripening, HWT fruit showed less CI, higher TP, and AoxA than control. It also showed an increased accumulation of phenolics, sugars, and some alkaloids that may be mediated by azelaic acid, glutamine, and tryptophan. The levels of N-feruloyl putrescine, esculeoside AII, and hydroxy-α-tomatine II were reduced. The better metabolic performance of HWT fruit under cold storage was associated with a higher accumulation of several metabolites (e.g., antioxidants and osmolytes) in ripening fruit. PRACTICAL APPLICATION: The identification of metabolites associated with the reduction of chilling injury (CI) symptoms in HWT tomato fruit extends the understanding of the mechanisms involved in CI tolerance. This information provides targets that could be used to develop strategies for preventing CI (e.g., genetic improvement of tomato, direct application of key metabolites). The application of such strategies will increase the economic value and decrease postharvest losses.

ADP-glucose pyrophosphorylase (AGPase) is a key enzyme of starch synthesis in seeds, tubers and fruits. UDP-glucose pyrophosphorylase (UGPase) is an important enzyme of sucrose metabolism in the cytosol while alkaline phosphatase (ALP) is a marker enzyme of the amyloplast that keeps the production of ADPG by removing PPi. Unripe banana accumulates starch in the pulp during development, while ripe fruits are characterized by the accumulation of soluble sugars. The aim of the study was to compare starch granule structure, carbohydrate levels, subcellular location and activities of three enzymes: AGPase, UGPase and ALP. Protein extracts from the cytosolic and amyloplastidial fractions were obtained from the pulp of banana fruit at three developmental stages (11, 16 and 21 weeks after flowering) and analyzed by electrophoresis and immunodetection. Protein profiles were similar during ripening, showing a main electrophoretic band at 50-55 kDa. Higher protein content was found in the cytosolic than in the amyloplastidial fraction. Starch granules and ALP activity were enriched in the amyloplast, whereas AGPase showed a subcellular distribution similar to UGPase. Immunoblot analysis also confirmed the presence of AGPase in both cytosol and amyloplast. AGPase activity was higher in the cytosol than in the amyloplast. Both AGPase activity and western blot band intensity were highest at 16 weeks. UGPase activity was highest at 21 weeks. We conclude that cytosolic production of ADP-glucose is not an exclusive feature of cereal endosperms due to plant breeding, but it also occurs in fruits of non-domesticated plants such as tropical banana (Musa acuminata). This work increases our understanding about pyrophosphorylase activities in the pulp of banana fruit.

Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) is a major pest of the tomato (Solanum lycopersicum L.) crop worldwide, mostly because of resistance to insecticide that has been associated with endosymbionts. Although knowledge of biotypes in the B. tabaci complex and its endosymbionts is critical for developing pest management strategies, limited information is available on the pest in the Culiacan Province of Mexico. In total, 249 samples of whiteflies were collected from tomato plants of four growers in the Culiacan Valley to analyze the genetic identity of the B. tabaci complex and its endosymbionts. PCR and phylogenetic analyses on the mitochondrial cytochrome oxidase I gene (mtCO1) revealed MEAM1, MED, and indigenous genetic groups in 53, 19, and 28%, respectively, of B. tabaci on tomatoes. Individual whiteflies were examined for endosymbionts through specific primers and phylogenetic analyses on the 16S rRNA and the 23S rRNA genes. Incidence of Portiera, Hamiltonella, Rickettsia, Wolbachia, and Cardinium was 81, 46, 28, 9, and 13%, respectively, in the B. tabaci samples analyzed. A new bacterium-endosymbiont in the genus Orientia was found and described in 63% of the samples of B. tabaci. A mixture of the endosymbionts Rickettsia+UAS_511+Cardinium was observed in 10% of samples of B. tabaci MED, while in the MEAM1 biotype, a combination of Hamiltonella+UAS_511 was in 32% of the samples analyzed. The study highlights the diversity and distribution of B. tabaci and its endosymbionts throughout the Culiacan Province and provides evidence for control of the insect pest.

El “permanente del tomate”, “manchado del tubérculo” o “zebra chip” en papa y “brotes cloróticos” del chile, son tres enfermedades descritas en México con signos coincidentes de aborto de flor, oscurecimiento de tejido vascular en la base del tallo y raíz de las plantas. Se ha mencionado la asociación entre estas enfermedades y la bacteria emergente Candidatus Liberibacter solanacearum (CLs) así como al psílido Bactericera cockerelli como su vector. Estas enfermedades, que en inicio se localizaban en tres estados de México se han diseminado a las principales regiones productoras de solanáceas, tanto en condiciones de campo como en invernadero. El objetivo del estudio fue conocer la presencia de CLs asociado a enfermedades que afectan los cultivos de tomate, para y chile en México. La bacteria se identificó por PCR del gen 16S de ADNr, clonación y secuenciación. La alineación de secuencias nucleotídicas se realizó con el método Clustal W y el árbol filogenético se construyó con el algoritmo de Neighbor-Joining a partir de distancias calculadas con el método de Tajima-Nei y un índice de Felsenstein de 1 000 réplicas, utilizando el software MEGA versión 5.05. En total se analizaron 167 muestras, de las cuales 86 resultaron positivas, provenientes de 14 estados de México. Se obtuvieron cinco secuencias nucleotídicas de Guanajuato, San Luis Potosí y Sinaloa correspondientes al tomate, papa y chile, adultos y huevecillos de B. cockerelli. El análisis de las secuencias mostró una identidad de 99.4% al comparase entre estas y hasta 99.8% con accesiones del GenBank descritas para CLs en EUA, Nueva Zelanda y Canadá.

Chickpea (Cicer arietinum L.) genotypes, nine kabuli from Mexico and 9 desi from other countries, were investigated for their phenolic profiles and antioxidant activity (AA). Phenolics in methanol extracts (ME) were analyzed by ultra-performance liquid chromatography coupled to diode array detection and mass spectrometry (UPLC-DAD-MS), whereas the AA was measured as Trolox equivalents (TE) by ABTS, DPPH and FRAP methods. Twenty phenolic compounds were identified in the ME and their levels showed a great variability among the chickpea genotypes. Phenolic acids and flavonoids were the most abundant compounds in kabuli and desi genotypes, respectively. The AA values (μmol TE/ 100 g dw) by ABTS (278-2417), DPPH (52-1650), and FRAP (41-1181) were mainly associated with the content of sinapic acid hexoside, gallic acid, myricetin, quercetin, catechin, and isorhamnetin, suggesting they are the main compounds responsible for the AA. The sum of the AA obtained for standards of these compounds evaluated at the concentration found in the extracts accounted for 34.3, 69.8, and 47.0% of the AA in the extract by ABTS, DPPH, and FRAP, respectively. In the AA by DPPH, most of the mixtures of these compounds resulted in synergistic interactions. Three desi genotypes with black seeds (ICC 4418, ICC 6306, and ICC 3761) showed the highest AA and flavonoids content, whereas the most promising kabuli genotypes were Surutato 77, Bco. Sin. 92, and Blanoro that showed the highest values of phenolic acids. These genotypes represent good sources of antioxidants for the improvement of nutraceutical properties in chickpea.

The fruit of 18 Solanum lycopersicum var. cerasiforme accessions from Mexico were evaluated for total phenolics (TP) by the Folin-Ciocalteau assay, phenolic profiles by high performance liquid chromatography-diode array detection-mass spectrometry (HPLC-DAD-MS), antioxidant activity (AoxA) by 2,2´-azino-bis(3-ethylbenzothiazolin)-6-sulfonic acid (ABTS), 2,2-diphenil-1-pycrilhydrazyl (DPPH), and oxygen radical absorbance capacity (ORAC), and antimutagenic activity (AmuA) by the Ames assay. TP was measured as Gallic Acid Equivalents (GAE) and the AoxA as Trolox Equivalents (TE). TP varied from 37 to 86 mg GAE 100 g−1 fresh weight (fw). The AoxA by ABTS (568-1187 µmol TE 100 g−1 fw) and DPPH (157-350 µmol TE 100 g−1 fw) correlated with TP and the levels of caffeoylquinic acids and rutin. The AmuA did not correlate with the levels of phenolics. Some accessions had higher AoxA and AmuA than those reported for commercial cultivars and also showed high levels of caffeoylquinic acids and rutin; thus, their consumption could have good health promoting effects.

Fusarium oxysporum f. sp. ciceris (Foc) es un hongo fitopatógeno que causa la enfermedad conocida como fusariosis vascular en el cultivo del garbanzo. En México, el garbanzo para exportación sólo se cultiva en el Noroeste (Sinaloa, Sonora y Baja California Sur). Considerando que Foc limita la producción de este cultivo y que en México no existe información referente a la identificación de las razas fisiológicas de este hongo, el objetivo fue aislar e identificar mediante pruebas moleculares y biológicas las razas fisiológicas del hongo presentes en las zonas de cultivo de garbanzo de la región del noroeste de México. Durante el periodo 2010-2014 se colectaron plantas de garbanzo con síntomas de marchitez y amarillez en diferentes localidades de los estados de Sinaloa, Sonora y Baja California Sur. El hongo se aisló a partir de pequeñas porciones de la planta, los cuales fueron sembradas en medio de cultivo papa- dextrosa-agar suplementado con pentanitroclorobenceno (PCNB) y cloranfenicol. Se aislaron y purificaron cultivos monospóricos, a los cuales se les extrajo el ADN para la identif icación de razas f isiológicas mediante PCR y secuenciación enzimática. Estas cepas se inocularon en líneas diferenciales de garbanzo, confirmándose por primera vez en México la identificación de las razas fisiológicas 0 y 5 de Foc.

Anthracnose of papaya fruit caused by the fungus Colletotrichum gloeosporioides is one of the most economically important postharvest diseases. Hot water immersion (HW) and calcium chloride (Ca) treatments have been used to control papaya postharvest diseases; however, the effect of the combination HW-Ca on the pathogen growth and the development of the disease in infected papaya fruit has been scarcely studied. The aim of this study was to evaluate the effect of the HW-Ca treatment on the in vitro growth of C. gloesporioides conidia and the quality of infected papaya. In vitro, the HW-Ca treated conidia showed reduced mycelial growth and germination. In vivo, the HW-Ca treatment of infected papaya delayed for 5 days the onset of the anthracnose symptoms and improved the papaya postharvest quality. The combined treatment HW-Ca was better than any of the individual treatments to inhibit the in vitro development of C. gloeosporioides and to reduce the negative effects of papaya anthracnose.

Hot water (HW) pre-treatment provides tolerance to chilling injury (CI) in tomato fruit, but little is known about the biochemical bases of this tolerance. The aim of this study was to identify proteins associated with CI tolerance in HW pre-treated tomato cv. Imperial. We used a comparative proteomic analysis between HW-treated (42 °C, 5 min) and non-treated fruit after cold storage (0, 10, and 20 days at 5 °C) and ripening (7 days at 21 °C); as well as real-time PCR to analyze the expression of genes encoding some selected proteins. Thirteen proteins were differentially expressed after 20 days of cold storage and 13 after the subsequent ripening period; polypeptides showing greater accumulation in HW-treated fruit included small heat shock proteins, antioxidant enzymes (thioredoxin peroxidase 1, superoxide dismutase, and ascorbate peroxidase), plant defense proteins (PR-10 and remorin 1) and RNA-binding chaperone protein (GR-RBP). In addition, non-treated fruit showed higher expression of enzymes involved in detoxification, carbohydrate, and energy metabolism, suggesting a low cellular efficiency in energy production due to severe structural damage. The hot water-induced chilling tolerance in tomato fruit appears to be related with the prevention of protein denaturation, activation of the antioxidant and defense systems, and the potential regulation of cold sensitive genes.

Candidatus Liberibacter solanacearum (CLs) es una bacteria asociada a la enfermedad “Permanente del Tomate” (PT) que ocasiona grandes daños a la producción de tomate (Solanum lycopersicum L.) en México. El uso de genotipos resistentes es la alternativa más sustentable para el manejo de enfermedades en plantas; sin embargo, actualmente no hay reportes de cultivares comerciales de tomate resistentes a CLs. Por lo anterior, el objetivo del presente estudio fue evaluar la respuesta a la infección con CLs en los cultivares Río Grande®, Moctezuma®, Marmande, DRK2180®, La Roca®, Bonny Best® y la línea avanzada UAS 2016. La evaluación se desarrolló en Culiacán, Sinaloa, México en condiciones de invernadero mediante un diseño de bloques completos al azar con cuatro repeticiones. La inoculación de CLs se llevó a cabo mediante su vector y la expresión de la enfermedad en la planta se registró durante siete semanas. La variabilidad genética de los genotipos fue analizada con el empleo de 15 microsatélites (SSR). Los resultados indicaron que la expresión de PT en UAS 2016 y Marmande fue significativamente menor que en Río Grande® y Moctezuma®, sin que DRK2180®, La Roca® y Bonny Best® mostraran diferencia significativa con respecto a esta última variedad. La diversidad genética total presentó un valor de 0.58 y un GST de 0.30, lo que indica que los genotipos presentaron variabilidad genética similar.

In this research, a healthy ready-to-eat expanded snack was produced using a maize/common bean (70/30%) mixture and characterized for its nutritional value, antioxidant potential, and phytochemical composition. Free and bound extracts were obtained and analyzed for phenolic profiles by ultra-high performance liquid chromatography with diode-array detector–tandem mass spectrometry (UPLC-DAD-MSn) and antioxidant activity (IC50) by ABTS and DPPH methods. Fatty acids and amino acid profiles were obtained by gas chromatography-mass spectrometry (GC-MS) and high-performance liquid chromatography (HPLC), respectively. Fourteen phenolic compounds were identified and quantified (mg/100 g, dw); the main compounds included three phenolic acids (ferulic, diferulic, p-coumaric) and three flavonoids (naringenin, kaempferol, methyl isoflavone). The IC50 (mg/mL) values obtained by ABTS (4.17 and 0.12) were smaller than those measured by DPPH (5.93 and 0.33). Seven fatty acids were also identified and the two most abundant were unsaturated (oleic, linoleic). The snack also showed an acceptable balance of amino acids according to the FAO, 2013 requirements, as well as a chemical score = 74.09 in vitro protein digestibility = 77.21%, C-PER = 1.53 and PDCAAS = 57.20%. The expanded snack could be source of bioactive, nutritional and antioxidant compounds for the improvement of the consumer's health.

A comparative proteomic approach was performed to analyze the differential accumulation of leaf proteins in response to the symbiosis between Solanum lycopersicum and the arbuscular mycorrhizal fungus (AMF) Rhizophagus irregularis. Protein profiling was examined in leaves from tomato plants colonized with AMF (M), as well as non-colonized plants fertilized with low phosphate (20 μM P; NM-LP) and non-colonized plants fertilized with regular phosphate Hoagland’s solution (200 μM P; NM-RP). Comparisons were made between these groups, and 2D-SDS-PAGE revealed that 27 spots were differentially accumulated in M vs. NM-LP. Twenty-three out of the 27 spots were successfully identified by mass spectrometry. Two of these proteins, 2-methylene-furan-3-one reductase and auxin-binding protein ABP19a, were up-accumulated in M plants. The down-accumulated proteins in M plants were associated mainly with photosynthesis, redox, and other molecular functions. Superoxide dismutase, harpin binding protein, and thioredoxin peroxidase were down-accumulated in leaves of M tomato plants when compared to NM-LP and NM-RP, indicating that these proteins are responsive to AMF colonization independently of the phosphate regime under which they were grown. 14-3-3 protein was up-accumulated in NM-RP vs. NM-LP plants, whereas it was down-accumulated in M vs. NM-LP and M vs. NM-RP, regardless of their phosphate nutrition. This suggests a possible regulation by P nutrition and AMF colonization. Our results demonstrate AMF-induced systemic changes in the expression of tomato leaf proteins, including the down-accumulation of proteins related to photosynthesis and redox function.

"La variación genética de maíz (Zea mays ssp. mays L.) en México ha sido estudiada especialmente en el centro-sur del país. El estado de Sinaloa (primero en producción) posee 23% de la variación genética racial nacional, pero su evaluación es escasa. Recolectamos 144 muestras de maíz (Tuxpeño Norteño, Vandeño, Onaveño, Elotero de Sinaloa, Tabloncillo, Tabloncillo Perla, Bofo, Jala, Blando de Sonora, Chapalote, Dulcillo del Noroeste y Reventador) en distintos puntos del estado con el objetivo de describir las características morfológicas y agronómicas relevantes para determinar un patrón de agrupación. Las accesiones fueron evaluadas en dos ambientes con un diseño de látice simple 12×12, analizando 27 variables. El ANDEVA detectó diferencias significativas entre accesiones (todas las variables), interacción genotipo × ambiente (anchura/longitud del grano) y ambientes en la espiga (longitud del tramo ramificado, número de ramificaciones primarias y longitud de la rama central), mazorca (diámetro/longitud, longitud del pedúnculo y de mazorca) y grano (volumen y peso/volumen). Los tres primeros componentes principales (CP) explicaron 64% de la varianza, donde las variables: número de hojas, diámetro y longitud de la mazorca; la anchura y espesor de grano; anchura/longitud del grano y floración; son las más importantes. La representación gráfica de los CP1 y CP2 reveló seis grupos y la de conglomerados cinco. Algunas accesiones poseían características compartidas con más de un grupo racial y su posición fue cercana a la de quienes compartían características. Se confirma una amplia diversidad genética de maíces nativos en Sinaloa."

The majority of snacks expanded by extrusion (SEE) are made with vegetable sources, to improve their nutritional content, it has been proposed to incorporate squid (Dosidicus gigas), due to its high protein content, low price and high availability. However, the interaction of proteins of animal origin with starch during extrusion causes negative effects on the sensory properties of SEE, so it is necessary to know the type of protein–carbohydrate interactions and their effect on these properties. The objective of this research was to study the interaction of proteins and carbohydrates of SEE elaborated with squid mantle, potato and corn. The nutritional composition and protein digestibility were evaluated, Fourier transform infrared (FTIR) and Differential Scanning Calorimetry (DSC) were used to study the formation of protein–starch complexes and the possible regions responsible for their interactions. The SEE had a high protein content (40–85%) and biological value (&gt, 93%). The melting temperature (Tm) was found between 145 and 225 °C, the Tm values in extruded samples are directly proportional to the squid content. The extrusion process reduced the amine groups I and II responsible for the protein–protein interaction and increased the O-glucosidic bonds, so these bonds could be responsible for the protein–carbohydrate interactions.

The application of a quarantine hot water treatment (HWT) induces chilling injury (CI) tolerance in mango fruit, but little is known about the mechanisms involved in this tolerance. The aim of this study was to identify metabolomic changes associated with HWT-induced CI tolerance in 'Keitt' mango fruit. Mature green fruit treated with hot water (HWT; 46.1 °C, 75-90 min) and non-treated (control) were stored for 20 d at 5 °C and ripened for 7 d at 21 °C. The incidence of chilling injury symptoms was registered as CI index. Methanol extracts of fruit peels were used for comparative metabolomics analyses by UPLC-DAD-MS and GC-MS. Total phenolics (TP) were analyzed by the Folin-Ciocalteu assay and the antioxidant activity (AA) was measured by ABTS, DPPH, and FRAP methods. HWT provided CI tolerance to mango fruit as evidenced by a low incidence of symptoms. Fifty-two and 14 metabolites were identified by UPLC-DAD-MS and GC-MS, respectively. These metabolites were classified as galloylquinic acids, gallic acid esters, gallotannins, gallic acid derivatives, benzophenone derivatives, xanthones, flavonoids, organic acids, sugars, fatty acids, and other metabolites (myo-inositol). The HWT before cold storage increased the abundance of galloylquinic acids, gallic acid esters, gallotannins, quercetin 3-O-rhamnoside, and myo-inositol; and it decreased the levels of mangiferin, ribose, malic acid, and palmitic acid. After cold storage and ripening, HWT fruit maintained higher levels of galloylquinic acids, gallic acid esters, gallotannins, quercetin 3-O-rhamnoside, mangiferin, myo-inositol, linolenic acid, and sugars than those in control fruit. HWT fruit also had higher values of TP and AA by the three methods. Control fruit had higher levels of citric acid, malic acid, palmitic acid, and ribose, as well as lower unsaturated/saturated fatty acid ratio. The HWT-induced CI tolerance in mango fruit appears to be associated with an increased content of antioxidants and osmoprotectant metabolites and a higher ratio of unsaturated/saturated fatty acids.

We previously demonstrated the effectiveness of a hot water (HW) treatment (40 °C for 7 min) to reduce chilling injury (CI) in tomato fruit and described the global transcriptional changes associated with CI tolerance and susceptibility after 2 weeks of cold storage. In this study we describe the early transcriptional responses of HW treated and non-treated tomato fruit after a short-term cold storage (2 and 24 h at 5 °C). RNA-Seq analysis detected a large number of differentially expressed genes that varied from 575 (control fruit after 2 h at 5 °C) to 5100 (HW treated fruit after 24 h at 5 °C). The protective effect of HW treatment against chilling stress was related first with the up-regulation of AP2/EREBP and C 2 H 2 -type zinc finger transcription factors, which are known to induce the expression of cold-regulated genes, and second with the up-regulation of chaperonins and peptidyl-prolyl cis – trans isomerases, which prevent the denaturation and aggregation of proteins. Also, some genes related to pathogen resistance (TIR, NBS and LRR families) were up-regulated in HW treated fruit after chilling, suggesting a crosstalk between biotic and abiotic stress responses. Transcriptional changes that were induced in HW treated fruit at early stages of chilling and maintained after long-term cold storage included the up-regulation of genes related to heat stress and the down-regulation of genes related to cell wall degradation.

Red arils of Pithecellobium dulce fruit, commonly known as guamuchil, show high antioxidant (AOx) and α-glucosidase inhibitory (IαG) activities, which have been mainly associated with the content of unknown anthocyanins. In this study, the AOx (i.e., DPPH and ABTS as Trolox equivalents, μmol TE/g) and IαG (as half-maximal inhibitory concentration, IC50, mg/mL) activities of the anthocyanin-rich fraction (ARF) obtained from red arils were contrasted with those of the methanol extract (ME), and the main ARF anthocyanins were characterized by HPLC-DAD-ESI-MS, GC-MS and 1H-NMR. The AOx and IαG values of the ARF (DPPH = 597.8; ABTS = 884.01; IαG = 0.06) were better than those of the ME (DPPH = 41.5; ABTS = 142.3; IαG = 17.5); remarkably, the ARF IαG value was about 42 times lower than that of acarbose. The main anthocyanins in ARF were pelargonidin 3-O-glucoside and cyanidin 3-O-glucoside. Thus, the consumption of red P. dulce arils could provide health benefits for prevention/treatment of chronic degenerative diseases such as diabetes.

Echeveria species (Crassulaceae) are used in traditional medicine and some of their biological activities are demonstrated (e.g. antimicrobial, anti-inflammatory, anticancer). However, their chemical composition has been scarcely studied. The methanol extracts (ME) of three Echeveria species (E. craigiana, E. kimnachii and E. subrigida) from Mexico were analyzed for the sterol (GC-MS) and phenolic (HPLC-DAD-ESI-MSn) composition. Eleven sterols were identified, E. kimnachii showed the highest total content (7.87 mg/g ME), and the main constituents were γ-sitosterol in E. craigiana (33.9%) and E. subrigida (54.4%), and lupenone in E. kimnachii (28.9%). The phenolic analysis showed differences among the Echeveria species, which contained flavonoids derivatives and tannins as the main components. The main flavonoids in E. craigiana were hexoside derivatives of quercetin and isorhamnetin, both with a 3-hydroxy-3-methylglutaroyl substituent; in E. subrigida hexosides of isorhamnetin, quercetin and kaempferol; and E. kimnachii showed the greatest diversity including proanthocyanidins and less common flavonoid derivatives of kaempferol O,O-disubstituted by acyl derivatives. The characteristic phytochemicals of each studied Echeveria species could be responsible of its specific biological activities and useful as chemotaxonomic markers. The kaempferol derivatives in E. kimnachii are rare in nature and they will be isolated and characterized., Journal of Applied Botany and Food Quality, Vol 91 (2018): Journal of Applied Botany and Food Quality

The variability in grain and starch characteristics and their relationship with the accumulation of starch granule associated proteins were investigated in five maize landraces of Northwest Mexico (Blando de Sonora, Chapalote, Elotero de Sinaloa, Reventador, and Tabloncillo). Significant differences were observed in grain hardness related traits, starch physicochemical properties, and structural properties. Blando de Sonora showed very soft grains, whereas the hardest grains were observed for Chapalote and Reventador. Starch granules isolated from landraces with hard grains contained more amylose and showed polygonal shapes, lower crystallinity and enthalpy of gelatinization, and greater retrogradation and proportion of long amylopectin chains. Proteomic analysis identified the enzymes granule-bound starch synthase I (GBSSI), starch synthase I and IIa, starch branching enzyme IIb, sucrose synthase 1, and pyruvate phosphate dikinase 2 as granule-associated proteins. The abundance of GBSSI correlated signif...

Rapid degradation of fresh-cut papaya limits its marketability. Hydrothermal treatments in combination with a calcium dip, applied to whole fruit before slicing, and also the application of chitosan as a coating film, have been found to have very good results in maintaining the quality of fresh-cut fruits. Based on these considerations, the aim of this study was to evaluate the effect of hydrothermal treatment (HT; 49 °C, 25 min) containing calcium chloride (Ca; 1%, w/v) followed by dipping in chitosan (Chit; 1%, w/v, 3 min) on the physical, chemical, and microbial qualities of papaya slices stored at 5 °C for 10 d. Pulp color, firmness, ascorbic acid, total phenolics, β-carotene, and lycopene were evaluated every 2 d while the microbial quality (mesophilics, psychrophilics, molds, and yeasts) was evaluated every 5 d. Fruit treated with HT-Ca and HT-Ca + Chit showed better color and firmness retention than Control and Chit. Papaya slices treated with HT-Ca + Chit had higher nutritional content and lower microbial growth at the end of storage. The application of the HT-Ca + Chit could be used to reduce deterioration processes, maintaining physical, chemical, and microbial qualities and increasing the shelf life of fresh-cut papaya stored at 5 °C.

Tomato fruit are horticultural products of great economic and nutritional value, whose transportation and marketing at low temperature are limited due to their susceptibility to develop chilling injury (CI). Hot water (HW) pre-treatments have been shown to reduce the CI symptoms in tomato fruit, but the molecular mechanisms involved in the acquisition of CI tolerance remain unclear. In the present work, a comparative transcriptomic analysis between HW treated and non-treated fruit before and after cold storage was carried out. RNA-Seq analysis detected a large number of differentially expressed genes that ranged from 2235 (heat shock) to 5433 (cold storage). Three clusters of genes were identified after 2 weeks of cold storage: the chilling-response included the down-regulation of genes involved in photosynthesis, metabolism of cell wall, lipid and ethylene, as well as the up-regulation of genes for trehalose synthesis and transcription factors (DOF and MYB); the chilling-susceptibility was associated with the down-regulation of genes involved in carotenoid biosynthesis, which correlates with the main CI symptom of uneven ripening; meanwhile, the chilling-tolerance was related to the up-regulation of genes for heat stress (heat shock proteins and heat shock transcription factors) and detoxification (glutathione S-transferases). The induced tolerance to CI in tomato fruit seems to be related first with the protection of cell wall and membranes integrity, and second with the restoration of ethylene biosynthesis and signaling.

Context:Helicteres vegae Cristóbal (Sterculiaceae) (Hv) and Heliopsis sinaloensis B.L. Turner (Asteraceae) (Hs) are endangered and poorly studied plant species; related plants have been used against chronic-degenerative and infectious diseases. Therefore, Hv and Hs could be sources of bioactive compounds against these illnesses. Objective: To determine the chemical composition and biological activities (antioxidant, antimutagenic and antimicrobial) of Hv and Hs leaves (L) and stems (S). Materials and methods: Methanol extracts (ME) of each plant/tissue were evaluated for their phytochemicals; phenolics (HPLC-DAD-ESI-MS); antioxidant activity (AA) (0.125–4 mg/mL) (DPPH, ABTS, ORAC and β-carotene discoloration); antimutagenicity (0.5 and 1 mg/plate) (Ames assay, tester strain Salmonella enterica serovar Typhimurium YG1024, 1-nitropyrene as mutagen); activity against human pathogens (1 mg/mL); and toxicity (0.01–2 mg/mL) (Artemia salina assay). Results: All ME showed flavonoids and triterpenes/steroids. The ME-SHv had the highest content of total phenolics (TP) (2245.82 ± 21.45 mg GAE/100 g d.w.) and condensed tannins (603.71 ± 1.115 mg CE/100 g d.w.). The compounds identified were flavonoids (kaempferol 7-O-coumaroylhexoside, and two kaempferol 7-O-rhamnosylhexosides) and phenolics [rosmarinic acid, and 3′-O-(8″-Z-caffeoyl) rosmarinic acid]. The ME-LHs showed the highest content of flavonoids (357.88 mg RE/g d.w.) and phenolic acids (238.58 mg CAE/g d.w.) by HPLC. The ME-SHv showed the highest AA. All ME were strong antimutagens (63.3-85.7%). Only the Hs extracts were toxic (ME-LHs, LC50 = 94.9 ± 1.7 μg/mL; ME-SHs, LC50 = 89.03 ± 4.42 μg/mL). Discussion and conclusions: Both Hv and Hs are potential sources of preventive and therapeutic agents against chronic-degenerative diseases.

There is a growing interest for an environment-friendly nixtamalization process. Nixtamalization with calcium salts generates a minimum level of polluting residues. The effect of a nixtamalization process with calcium carbonate (NCC) on the indigestible carbohydrate content and starch digestibility of tortillas was evaluated. Traditional and NCC tortillas showed lower moisture content than commercial tortillas. Similar protein, ash, and carbohydrate content were found for the three tortillas, but NCC tortillas showed the highest lipid content. The NCC tortilla had the highest dietary fiber content, with the highest insoluble dietary fiber level. Fresh and stored (96 h) NCC and traditional tortillas showed similar resistant starch content. Fresh traditional tortilla showed the highest slowly digestible starch (SDS), but upon storage the rapidly digestible starch (RDS) content of NCC tortilla decreased. Fresh traditional and NCC tortillas had lower predicted glycemic index (pGI) than commercial tortillas, and upon storage, the three tortillas presented lower pGI values than their fresh counterparts. Consumption of tortillas produced with the NCC can produce positive effects in the human health.

Genetic analysis using quality protein maize (QPM) recombinant inbred lines derived from K0326Y QPM and W64Ao2 identified three quantitative trait loci (QTL) in bins 1.06, 7.02 and 9.03 associated with opaque2 endosperm modification. We evaluated the effects of these QTLs on protein accumulation and starch physicochemical properties. The QTL in bin 1.06 is close to α-zein genes, and vitreous individuals with this QTL had increased accumulation of 19-kDa α-zein, 27-kDa γ-zein and legumin-1. The QTL in bin 7.02 corresponds to the γ-zein locus, and greater accumulation of this protein was found in vitreous individuals. The QTL in bin 9.03 is close to starch biosynthetic genes; greater accumulation of granule-bound starch synthase and amylose was observed in vitreous kernel samples with this locus and that in bin 1.06, as well as less gelatinization enthalpy and crystallinity. Vitreous kernels contained angular-shaped/compact starch granules and more short-intermediate length chains of amylopectin. These results support that endosperm modification in QPM is associated with increased accumulation of γ-zein and other storage proteins, but also show that synthesis of less crystalline starch with more amorphous regions at the periphery of granules, which favor their packing and association with endosperm proteins, may also be an important factor.

In the state of Sinaloa Mexico, traditional farmers still cultivate maize accessions with a wide diversity of morphological characteristics, but the gene reservoir maintained in these populations has been poorly studied and it is being lost due to changes in land use and the adoption of hybrid commercial varieties. The aim of this study was to evaluate the genetic diversity of some of these maize populations to contribute to their preservation. Twenty eight accessions were used for the analysis. DNA was extracted from 396 individuals and probed with 20 microsatellites distributed across the maize genome. A total of 121 alleles were obtained (average of 6.1 alleles per locus) and a total genetic diversity of 0.72. The UPGMA-cluster analysis, model-based population structure and principal component analysis revealed three major groups, one formed mainly by accessions of races typical of the Northwestern lowlands (Chapalote, Dulcillo del Noroeste, Tabloncillo Perla, Blando de Sonora and Elotero de Sinaloa) and the other two with accessions mainly from Tabloncillo and Tuxpeno. The high number of alleles per locus and total genetic diversity found in this study demonstrate a broad genetic basis of the accessions of maize landraces from Sinaloa, representing a gene reservoir useful in breeding programs.

The potential use of quality protein transgenic maize (genetically modified maize with the cDNA of amarantin) for preparation of flour and tortillas through an extrusion lime cooking process was investigated. Tortillas from extruded transgenic maize flour had similar physicochemical and sensory properties than those from the commercial brand MASECA; however, the former had the highest (P < 0.05) protein content (12.91 vs 8.93%, db), essential amino acids content, calculated protein efficiency ratio (CPER; 2.27 vs 0.90) and protein digestibility corrected amino acid score (PDCAAS; 55.54 vs 30.18%) and therefore they were nutritionally better. The use of transgenic maize for flour and tortilla preparation through an extrusion lime cooking process may have a positive impact on the nutritional status of people from countries where maize is the basic staple food. It also represents an alternative process to nixtamalization that requires little energy and water, it does not generate wastewater, and all components of the maize kernel are retained.

Tomato apex necrosis virus (ToANV) is a new virus that causes important damage in tomato crops from the Culiacan Valley, Sinaloa, Mexico. To understand the relationship between ToANV and its vector Bermisia tabaci (Hemiptera: Aleyrodidae) (Gennadius) biotype B, laboratory and greenhouse trials were completed to: 1) determine the acquisition and inoculation access periods of ToANV by B. tabaci from tomato to tomato, 2) understand the transmission efficiency at different B. tabaci population densities, 3) estimate the time from inoculation of the virus at different B. tabaci densities to manifestation of symptoms in the plants, and 4) determine the retention time of the virus by the insect vector. The presence of the virus in plants was determined by reverse transcription-polymerase chain reaction amplification ofa 795-bp fragment (GenBank JN704068), which is phylogenetically related to ToANV (GenBank EF063242). The results showed that B. tabaci is an effective vector for ToANV with relatively long acquisition (12 h) and inoculation (9 h) access periods; a single adult is capable of transmitting and retaining the virus for up to 7d, suggesting a persistent mode of transmission. These results will help in the development of management strategies for controlling the vector and the disease.

Salmonellosis is an important zoonotic disease but little is known about the role that free-living animals play as carriers of this pathogen. Moreover, the primary route of infection in the wild needs to be elucidated. The aim of this study was to determine the source and the route of transmission of Salmonella enterica serovar Albany (S. Albany) infection in captive zoo wild animals in the Culiacán Zoo. A total of 267 samples were analyzed including 220 fecal samples from zoo animals, 15 fecal samples from rodents, 5 pooled samples each of two insects (Musca domestica and Periplaneta americana), and 22 samples of animal feed. We detected S. Albany in 28 (10.5%) of the samples analyzed, including in samples from raw chicken meat. Characterization of isolates was performed by serotyping and pulsed-field gel electrophoresis. All isolates shared a single pulsed-field gel electrophoresis profile, indicating a possible common origin. These data suggest that the infected meat consumed by the wild felines was the primary source of infection in this zoo. It is likely that the pathogen was shed in the feces and disseminated by insects and rats to other locations in the zoo.

The snack foods market is currently demanding healthier products. A ready-to-eat expanded snack with high nutritional and antioxidant value was developed from a mixture (70:30) of whole amarantin transgenic maize (Zea mays L.) and black common bean (Phaseolus vulgaris L.) by optimizing the extrusion process. Extruder operation conditions were: feed moisture content (FMC, 15–25 %, wet basis), barrel temperature (BT, 120–170 °C), and screw speed (SS, 50–240). The desirability numeric method of the response surface methodology (RSM) was applied as the optimization technique over four response variables [expansion ratio (ER), bulk density (BD), hardness (H), antioxidant activity (AoxA)] to obtain maximum ER and AoxA, and minimum BD, and H values. The best combination of extrusion process variables for producing an optimized expanded snack (OES, healthy snack) were: FMC = 15 %/BT = 157 °C/SS = 238 rpm. The OES had ER = 2.86, BD = 0.119 g/cm 3 , H = 1.818 N, and AoxA = 13,681 μmol Trolox equivalent (TE)/100 g, dry weight. The extrusion conditions used to produce the OES increased the AoxA (ORAC: +18 %, ABTS:+20 %) respect to the unprocessed whole grains mixture. A 50 g portion of OES had higher protein content (7.23 vs 2.32 g), total dietary fiber (7.50 vs 1.97 g), total phenolic content (122 vs 47 mg GAE), and AoxA (6626 vs 763 μmol TE), and lower energy (169 vs 264 kcal) than an expanded commercial snack (ECS = Cheetos™). Because of its high content of quality protein, dietary fiber and phenolics, as well as high AoxA and low energy density, the OES could be used for health promotion and chronic disease prevention and as an alternative to the widely available commercial snacks with high caloric content and low nutritional/nutraceutical value.

The opaque2 (o2) mutation in maize (Zea mays L.) increases the content of free amino acids (FAA) in the endosperm. We investigated the basis of this trait by using recombinant inbred lines from a cross of Oh545o2 (high FAA) and Oh51Ao2 (low FAA) to identify quantitative trait loci (QTL) for FAA content and to determine their effect on FAA composition and protein accumulation. Mapping identified six QTLs that accounted for 71% of the phenotypic variation. Two QTLs in bins 4.01 and 7.02 are close to α-zein genes; high FAA individuals with these QTLs had reduced accumulation of α-zein 19 kDa isoforms and increased FAA abundant in α-zeins. A QTL in bin 3.03 is close to a gene encoding triose phosphate isomerase (tpi4) and a higher expression of this enzyme was found in high FAA individuals. Other differentially expressed proteins included vicilin-like globulins and the enzymes glyceraldehyde-3-phosphate dehydrogenase, enolase-2, sorbitol dehydrogenase and granule-bound starch synthase. The results suggest that the increased levels of FAA in o2 endosperm are mainly due to the reduction of storage proteins and the failure to incorporate their amino acids into other proteins, as well as the alteration of carbohydrate metabolism that may favor amino acid biosynthesis.

In Mexico, common bean grain has been used for centuries in Mexican population diet. The organoleptic and nutritional properties and other characteristics are related to protein composition. Proteomics approaches have been employed to detected genetic variation of soybean and other crops, but there is not a report of this technologies applied to common beans. The proteomics characterization of three genotypes of common bean produced in Sinaloa was realized. The genotypes: Azufrado Higuera, Azufrado Noroeste and Azufrado Regional 87 were evaluated. A protein extraction protocol based on TCA/acetone precipitations was optimized in order to perform Twodimensional gel electrophoresis. Gels analysis shown significant differences between all the genotypes, but a strong homology was detected between Azufrado Higuera and Azufrado Noroeste seed storage proteins, but not with Azufrado Regional 87. These results are the first attempt to employ proteomics technique to common beans studies.

Changes in phenylalanine ammonia-lyase (PAL) activity and chilling injury (CI) index were evaluated in tomato (Lycopersicon esculentum M.) during storage and ripening. Fruits were stored at 12C, 4C and from 12 to 4C (gradual cooling, decreasing 2C from 12 to 8C at 3 days intervals and then at 4C) and 85–90% relative humidity for up to 21 days followed by a ripening period of 8 days at 21C. PAL activity showed an increase during the storage period, showing a maximum value after 21 days of storage at 12–4C and 4C. Development of CI symptoms was coincident, and closely correlated with the increase in PAL activity. Gradual cooling reduced 1.5-fold the CI symptoms. It appears that low temperatures induced the tomato fruit defense response, as suggested by the behavior of PAL activity, and gradual cooling increased chilling tolerance. PRACTICAL APPLICATIONS The storage of tomatoes at temperatures below 12C could lead to chilling injury, a physiological disorder that affects the quality of tropical and subtropical fruits resulting in commercial losses or reduced consumer acceptability. In this study, a gradual cooling storage treatment was used to induce tolerance of tomato against this disorder. The results of this research showed that gradual cooling could be an alternative for using temperatures below 12C for the storage of tomato, increasing its shelf life, maintaining the quality and benefiting the distribution chain.

Tomato (Solanum lycopersicum) fruit is susceptible to chilling injury (CI), a physiological disorder caused by low, non-freezing temperatures that affects fruit postharvest quality. Little is known about the biochemical basis of CI, and the aim of this study was to identify proteins related to this disorder in ‘Imperial’ tomato fruit. CI and protein expression changes were analyzed during fruit ripening (0, 4, 8, and 12 days at 21 °C) after storage under chilling (5 °C) and non-chilling conditions (21 °C) for 5, 15, and 25 days. The main CI symptoms observed were uneven fruit ripening and color development, pitting, and decay. Protein analysis of two-dimensional gels showed that 6% of the detected spots (≈300) changed their expression in response to cold. The identified proteins are involved in carbon metabolism, oxidative stress, photosynthesis, and protein processing and degradation; two were related to cold stress, showing higher accumulation in non-damaged tissue of chilled fruit: thioredoxin peroxidase (TPxI) and glycine-rich RNA-binding protein (GR-RBP). This is the first report suggesting an important role for TPxI and GR-RBP in cold response during tomato fruit ripening, and they may be acting through redox sensing and regulation of gene expression at low temperature. These enzymes and the other chilling-related proteins might be working together to maintain the cellular homeostasis under cold stress conditions.

Waxed and nonwaxed mature green tomato fruits were stored at 12C (nonchilled) or 5C (chilled) for 5, 10, 15 and 20 days before being transferred to 22C for 3, 6, 9 and 12 days, were evaluated for weight loss, chemical composition, skin color, chilling injury (CI) index and pigment content. Waxed fruits showed a delay in weight loss, color development and ripening. The sensitivity of tomato fruit to CI was reduced in waxed fruits, which showed a delay in the appearance of symptoms. A delay in chlorophyll degradation and lycopene synthesis was observed as a result of the use of wax and low temperature. Waxing of tomato fruits allowed their storage at temperatures below critical reducing CI sensitivity and maintaining quality giving more time for marketing. PRACTICAL APPLICATIONS Nowadays, local tomato producers use wax on fruits as an everyday practice to carry postharvest fungicides and to improve brightness. They store tomato fruits at nonchilling temperature (12C) because lower temperatures would cause chilling injury and irregular ripening. In this way, it is interesting that waxing tomato fruits allow reducing their storage temperature, protecting them from chilling injury and maintaining their quality and correct color change and ripening; thereby producers and sellers have more days to position their fruits with no extra cost.

Nixtamalised flour from transgenic maize (genetically modified maize with the cDNA of amarantin) and its tortillas were evaluated for some technological and nutritional properties and compared to the com- mercial brand MASECA TM . Nixtamalised transgenic maize flour (NTMF) showed higher protein content, total colour difference, pH, water solubility index, essential amino acids content and lower Hunter ''L" value, water absorption index, resistant starch and retrograded resistant starch than MASECA TM

Nixtamalized and extruded flours from quality protein maize (QPM, V-537C) and tortillas made from them were evaluated for some technological and nutritional properties and compared with the commercial brand MASECA. Both QPM flours showed higher (P < 0.05) protein content, total color difference, pH, available lysine, and lower (P < 0.05) total starch content, Hunter L value, water absorption index, gelatinization enthalpy, resistant starch, and retrograded resistant starch than nixtamalized MASECA flour. Tortillas from nixtamalized and extruded QPM flours had higher contents of essential amino acids than tortillas from MASECA flour, except for leucine. Tortillas from processed QPM flours also showed higher (P < 0.05) values of the nutritional indicators calculated protein efficiency ratio (C-PER 1.80–1.85 vs. 1.04), apparent and true in vivo protein digestibility (78.4-79.1 vs. 75.6% and 76.4–77.4 vs. 74.2%, respectively), PER (2.30–2.43 vs. 1.31), net protein retention (NPR; 2.88–2.89 vs. 2.11),...

The effects of solid state fermentation (SSF) on physicochemical and nutritional properties of chickpea flour were studied. Fermented (tempeh) flour showed higher particle size index, gelatinization temperature, dispersability and resistant starch content, and lower gelatinization enthalpy and water solubility than unfermented flour. SSF increased the content of the essential amino acids (EAA) Ile, total sulphur (Met + Cys), total aromatic (Phe + Tyr), and Thr in 37, 41, 107, and 39 g kg −1 protein, respectively; Trp content decreased 8 g kg −1 protein. Total sulphur (EAA score = 0.87) was limiting in unfermented flour and Trp (0.93) in tempeh flour. SSP improved the in vitro and true protein digestibility (72.2–83.2% and 83.7–88.8%, respectively), protein efficiency ratio (PER, 1.59–2.31), cPER (1.54–2.21), and corrected protein digestibility (0.73–0.89). Chickpea tempeh flour may be considered for the fortification of widely consumed legume-based food products.

Fusarium oxysporum f. sp. ciceris (Foc) es un hongo fitopatógeno que causa la enfermedad conocida como fusariosis vascular en el cultivo del garbanzo. En México, el garbanzo para exportación sólo se cultiva en el Noroeste (Sinaloa, Sonora y Baja California Sur). Considerando que Foc limita la producción de este cultivo y que en México no existe información referente a la identificación de las razas fisiológicas de este hongo, el objetivo fue aislar e identificar mediante pruebas moleculares y biológicas las razas fisiológicas del hongo presentes en las zonas de cultivo de garbanzo de la región del noroeste de México. Durante el periodo 2010-2014 se colectaron plantas de garbanzo con síntomas de marchitez y amarillez en diferentes localidades de los estados de Sinaloa, Sonora y Baja California Sur. El hongo se aisló a partir de pequeñas porciones de la planta, los cuales fueron sembradas en medio de cultivo papa-dextrosa-agar suplementado con pentanitroclorobenceno (PCNB) y cloranfenicol. Se aislaron y purificaron cultivos monospóricos, a los cuales se les extrajo el ADN para la identificación de razas fisiológicas mediante PCR y secuenciación enzimática. Estas cepas se inocularon en líneas diferenciales de garbanzo, confirmándose por primera vez en México la identificación de las razas fisiológicas 0 y 5 de Foc.

Rapid degradation of fresh-cut papaya limits its marketability. Hydrothermal treatments in combination with a calcium dip, applied to whole fruit before slicing, and also the application of chitosan as a coating film, have been found to have very good results in maintaining the quality of fresh-cut fruits. Based on these considerations, the aim of this study was to evaluate the effect of hydrothermal treatment (HT; 49 °C, 25 min) containing calcium chloride (Ca; 1%, w/v) followed by dipping in chitosan (Chit; 1%, w/v, 3 min) on the physical, chemical, and microbial qualities of papaya slices stored at 5 °C for 10 d. Pulp color, firmness, ascorbic acid, total phenolics, β-carotene, and lycopene were evaluated every 2 d while the microbial quality (mesophilics, psychrophilics, molds, and yeasts) was evaluated every 5 d. Fruit treated with HT-Ca and HT-Ca + Chit showed better color and firmness retention than Control and Chit. Papaya slices treated with HT-Ca + Chit had higher nutritional content and lower microbial growth at the end of storage. The application of the HT-Ca + Chit could be used to reduce deterioration processes, maintaining physical, chemical, and microbial qualities and increasing the shelf life of fresh-cut papaya stored at 5 °C.