Assessment of macadamia kernel quality defects by means of near infrared spectroscopy (NIRS) and nuclear magnetic resonance (NMR)

Macadamia kernels are visually sorted based on the presence of quality defects by specialized labors. However, this process is not as accurate as non-destructive methods such as near infrared spectroscopy (NIRS) and nuclear magnetic resonance (NMR). Thus, NIRS and NMR in combination with chemometrics have become established non-destructive method for rapid assessment of quality parameters in the food and agricultural sectors. Therefore, the quality of macadamia kernel was assessed by NIRS and NMR using chemometric tools such as PCA-LDA and GA-LDA to evaluate external kernel defects. Macadamia kernels were classified as: 1 = good, marketable kernels without defects; 2 = kernels with discoloration; 3 = immature kernels; 4 = kernels affected by mold; and 5 = kernels with insect damage. Using NIRS, the GA-LDA resulted in an accuracy and specificity of 97.8% and 100%, respectively, to classify good kernels. On the other hand, PCA-LDA technique resulting in an accuracy higher than 68% and specificity of 97.2% to classify immature kernels. For NMR, PCA-LDA resulted in an accuracy higher than 83% and GA-LDA resulted in an accuracy of 100%, both to classify kernels with insect damage. NIRS and NMR spectroscopy can be successfully used to classify unshelled macadamia kernels based on the defects. However, NIRS out-performed NMR based on the higher accuracy results

A cultivar afeta a susceptibilidade ao escurecimento de pedaços recém cortados de carambola

Consumption of freshly-cut horticultural products has increased in the last few years. The principal restraint to using freshly-cut carambola is its susceptibility to tissue-browning, due to polyphenol oxidase-mediated oxidation of phenolic compounds present in the tissue. The current study investigated the susceptibility to browning of star fruit slices (Averrhoa carambola L.) of seven genotypes (Hart, Golden Star, Taen-ma, Nota-10, Malásia, Arkin, and Fwang Tung). Cultivar susceptibility to browning as measured by luminosity (L*) varied significantly among genotypes. Without catechol 0.05 M, little changes occurred on cut surface of any cultivars during 6 hour at 25°C, 67% RH. Addition of catechol led to rapid browning, which was more intense in cvs. Taen-ma, Fwang Tung, and Golden Star, with reduction in L* value of 28.60%, 27.68%, and 23.29%, respectively. Browning was more intense in the center of the slices, particularly when treated with catechol, indicating highest polyphenol oxidase (PPO) concentration. Epidermal browning, even in absence of catechol, is a limitation to visual acceptability and indicates a necessity for its control during carambola processing. Care must be given to appropriate selection of cultivars for fresh-cut processing, since cultivar varied in browning susceptibility in the presence of catechol.O consumo de produtos hortícolas minimamente processados tem aumentado nos últimos anos. Entretanto, a principal restrição para o uso de carambolas minimamente processadas é sua susceptibilidade ao escurecimento devido a oxidação de compostos fenólicos presentes nos tecidos que é mediado pela polifenoloxidase (PPO). Investigou-se a suscetibilidade ao escurecimento de fatias de carambola (Averrhoa carambola L.) de sete cultivares (Hart, Golden Star, Taen-ma, Nota-10, Malásia, Arkin e Fwang Tung). A suscetibilidade das cultivares ao escurecimento, medido através da luminosidade (L*), variou significativamente entre cultivares. Sem a aplicação do catecol (0,05 M), ocorreram poucas mudanças de coloração na superfície cortada dos pedaços das diferentes cultivares durante 6 horas a 25ºC, 67% U.R. A adição de catecol levou ao rápido escurecimento, que foi mais intenso nas cvs. Taen-ma, Fwang Tung e Golden Star, com redução no valor de L* de 28,60%, 27,68% e 23,29%, repectivamente. O escurecimento foi mais intenso no centro dos pedaços, particularmente quando tratados com catecol, indicando grande atividade da PPO. O escurecimento da epiderme, mesmo na ausência de catecol, é uma limitação visual à aceitação e indica a necessidade de seu controle durante o processamento da carambola. Cuidados devem ser tomados quanto à recomendação de cultivares para o processamento mínimo, uma vez que estas apresentam variações quanto à susceptibilidade ao escurecimento na presença de catecol

Fresh cut ‘Keitt’ mango treated with calcium chloride

[POR] O escurecimento e amolecimento de mangas minimamente processadas são fatores de redução da sua vida de prateleira, podendo ser minimizado pela adição de cloreto de cálcio. Este trabalho teve por objetivo testar a utilização do cloreto de cálcio na manutenção da qualidade e no prolongamento da vida útil de produtos minimamente processados (PMP) de mangas ‘Keitt’. Os frutos foram selecionados, lavados com detergente, sanitizados (200mg.L- 1 de cloro) e estocados, por 12 horas a 10ºC. O processamento foi a 12ºC e constou de descasque, corte em fatias longitudinais, enxágüe com solução de cloro (20mg.L-1), escorrimento e tratamento com soluções de CaCl2 (0%, 1,5% e 3,0%), por imersão (3 minutos). Após escorrimento, foram acondicionados em embalagem de PET e armazenados a 3ºC. Foram avaliados, a cada 3 dias quanto aos conteúdos de ácido ascórbico, sólidos solúveis (SS), acidez titulável e de carboidratos solúveis e redutores, assim como, quanto ao pH , resistência e coloração (luminosidade, cromaticidade e ângulo Hue) da polpa. Durante o armazenamento houve pequena variação nos teores de ácido ascórbico, sólidos solúveis, carboidratos solúveis e redutores e valores de pH e diminuição na acidez titulável. Os produtos tratados com cálcio apresentaram maiores teores de ácido ascórbico, acidez titulável e carboidratos redutores e menores teores de sólidos solúveis e carboidratos solúveis e pH, quando comparados aos não tratados. Os produtos não tratados apresentaram-se mais escuros e com cor mais alaranjada, indicado pela luminosidade e ângulo Hue. O cálcio não foi eficiente em atrasar ou inibir o amolecimento. Os produtos tratados com cloreto de cálcio apresentavam-se com aparência superior aos não tratados, os quais se apresentavam mais escuros e moles. O cloreto de cálcio foi eficiente em manter a qualidade e as características químicas e físicas de produtos minimamente processados de manga ‘Keitt’. [ENG] Browning and softening of fresh cut mangoes are factors of shelf life declining that could be minimized by the addition of calcium chloride. This work aimed to test the use of the calcium chloride in quality maintenance and shelf life extending of fresh cut ‘Keitt’ mango. Fruits were selected, washed with detergent, sanitised (200mg.L-1 of chlorine) and stored, for 12 hours at 10ºC. The processing was at 12ºC and it and it consisted in peeling, cutting in longitudinal slices, dipping in sanitised water (20mg.L-1), draining and treatment with solutions of CaCl2 (0%, 1.5% and 3.0%), by immersion (3 minutes). After draining, they were packed in PET trays and stored at 3ºC. Every 3 days, the products were measured for contents of ascorbic acid, soluble solids, titratable acidity and soluble and reducing sugars, as well as, pH, firmness and colour (brightness, chroma and Hue angle) of the pulp. During the storage there was a slight variation in ascorbic acid, soluble solids, soluble and reducers sugars contents and pH values and decreasing in the acidity. Products treated with calcium presented higher contents of ascorbic acid, titratable acidity and reducers sugars and lower soluble solids and soluble sugar and pH, when compared to the non treated slices. The non treated products were darker and more yellow-orange, indicated by the brightness and Hue angle. Calcium was not efficient on delaying or inhibiting the softening. The treated products with calcium chloride had superior appearance in relation to the non treated, which were darker and softer. The calcium chloride was efficient in maintaining the quality and the chemical and physics characteristics of fresh cut ‘Keitt' mangoes.FAPEMIG pelo apoio financeiro, à FAPESP (02/00336-4), pela concessão da bolsa de doutorado e à CAPES (BEX 1336-04/5) pela bolsa de estágio no exterior

Total anthocyanin content determination in intact açaí (Euterpe oleracea Mart.) and palmitero-juçara (Euterpe edulis Mart.) fruit using near infrared spectroscopy (NIR) and multivariate calibration

AbstractThe aim of this study was to evaluate near-infrared reflectance spectroscopy (NIR), and multivariate calibration potential as a rapid method to determinate anthocyanin content in intact fruit (açaí and palmitero-juçara). Several multivariate calibration techniques, including partial least squares (PLS), interval partial least squares, genetic algorithm, successive projections algorithm, and net analyte signal were compared and validated by establishing figures of merit. Suitable results were obtained with the PLS model (four latent variables and 5-point smoothing) with a detection limit of 6.2gkg−1, limit of quantification of 20.7gkg−1, accuracy estimated as root mean square error of prediction of 4.8gkg−1, mean selectivity of 0.79gkg−1, sensitivity of 5.04×10−3gkg−1, precision of 27.8gkg−1, and signal-to-noise ratio of 1.04×10−3gkg−1. These results suggest NIR spectroscopy and multivariate calibration can be effectively used to determine anthocyanin content in intact açaí and palmitero-juçara fruit

Postharvest changes and respiratory pattern of bacuri fruit (Platonia insignis Mart.) at different maturity stages during ambient storage

ABSTRACT Bacuri (Platonia insignis, Mart.) is one of the most important among Amazonian fruits. However, little is known about its postharvest physiology, such as maturity stages, changes during ambient storage, and respiratory pattern. Fruits were harvested at three maturity stages based on epicarp colour: dark green, light green, and turning (50% yellow), in order to determine colour modification and respiratory pattern during ambient storage (25.2 0 C, 75.1 % RH). Fruit of all maturity stages showed, after three days of harvest, a non-climacteric respiratory pattern, with turning fruit presenting the highest CO 2 production rate until the fourth storage day (177.63 mg.CO 2 .kg -1 .h -1 ). Yellowing increased throughout storage as related to lightness, chromaticity, and hue angle reductions. Turning fruit can be stored at ambient conditions for up to 10 days without any loss in marketability. KEY WORD

Conventional and alternative pre-harvest treatments affect the quality of ‘Golden Delicious’ and ‘York’ apple fruit

Apple trees cv. ‘Golden Delicious’ and ‘York’ were sprayed from bloom to fruit maturity with different products to evaluate the effect of pre-harvest treatments on fruit quality, including insect/disease damage and physicochemical fruit traits. Apple trees were assigned to five treatments: unsprayed (control), holistic solution (foliar nutrients and probiotics), insecticides, antimicrobials (fungicides and antibiotics), and a combination of antimicrobials + insecticides. The treatments started soon after bloom and were carried out every two weeks until fruit were ready to harvest. Diseases such as sooty blotch (complex of several fungi) and flyspeck (Zygophiala jamaicensis Mason) were the major source of damage on fruits. ‘Golden Delicious’ trees had a higher percentage of undamaged fruit than ‘York’, but all trees had some percentage of damaged fruit. Damage was most severe in the control (unsprayed) and insecticide treatments, intermediate in the holistic treatment, and much lower in the antimicrobial and antimicrobial + insecticide treatments (p < 0.003 for all comparisons). There was also a significant interactive effect (p < .0001) of cultivars and pre-harvest spray treatment on apple fruit mass. For both cultivars there was a strong effect of spray treatment on size, with larger apples produced in the antimicrobial and antimicrobial + insecticide treatments, but these effects were more pronounced in 'York' than in 'Golden Delicious' apples. ‘Golden Delicious’ trees produced 1.4-fold heavier and bigger fruits compared to ‘York’ and ‘Golden Delicious’ fruit were more mature than ‘York’ at harvest. Pre-harvest treatments also affected other quality parameters of apple fruit, such as soluble solids content (SSC) and starch-iodine index. Using partial least squares discriminant analysis (PLS-DA), ‘Golden Delicious’ fruit could be well classified according to the holistic, antimicrobial, and antimicrobial + insecticide treatments. Control and insecticide samples clustered together, indicating similarities between fruit quality. Overall, pre-harvest spray treatment affected the quality of ‘Golden Delicious’ and ‘York’ apples, mainly the fruit mass and disease infection

Estimation and classification of popping expansion capacity in popcorn breeding programs using NIR spectroscopy

One of the most important quality traits in popcorn breeding programs is the popping expansion (PE) capacity of the kernel, which is the ratio of the volume of the popcorn to the weight of the kernel. In this study, we evaluated whether near infrared spectroscopy (NIR spectroscopy) could be used as a tool in popcorn breeding programs to routinely predict and/or discriminate popcorn genotypes on the basis of their PE. Three generations (F1, F2, and F2:3) were developed in three planting seasons by manual cross-pollination and self-pollination. A total of 376 ears from the F2:3 generation were selected, shelled, and subjected to phenotypic analysis. Genetic variability was observed in the F2 and F2:3 generations, and their average PE value was 31.5 ± 6.7 mL.g-1. PE prediction models using partial least square (PLS) regression were developed, and the root mean square error of calibration (RMSEC) was 6.08 mL.g-1, while the coefficient of determination (RC 2) was 0.26. The model developed by principal component analysis with quadratic discriminant analysis (PCA-QDA) was the best for discriminating the kernels with low PE (≤ 30 mL.g-1) from those with high PE (> 30 mL.g-1) with an accuracy of 78%, sensitivity of 81.2%, and specificity of 72.2%. Although NIR spectroscopy appears to be a promising non-destructive method for assessing the PE of intact popcorn kernels for narrow breeding populations, greater variability and larger sample sizes would help improve the robustness of the predictive and classificatory models

In vitro control of phytopathogenic fungi and damping-off of tomato by Bacillus velezensis LABIM40 (CMRP 4489)

The in vitro antagonistic activity of Bacillus velezensis LABIM40 (strain CMRP 4489) was assessed against Alternaria linariae, Botryotinia squamosa, Colletotrichum lindemuthianum, Gibberella zeae, and Rhizoctonia solani. An experiment was conducted using treated seeds under growth chamber conditions to determine the impact of various LABIM40 formulations on tomato seedling growth and the biocontrol of damping-off caused by R. solani. The treatments included the use of LABIM40 cell suspension, LABIM40 cell-free supernatant (CFS), 10 times concentrated CFS (10× CFS), commercial products based on Bacillus amyloliquefaciens (CP_1) and Bacillus subtilis (CP_2), and water. The effects of these products were assessed on tomato seedlings grown in sterile substrate or substrate inoculated with R. solani. In a dual culture test, B. velezensis LABIM40 inhibited the mycelial growth of the aforementioned fungal pathogens by 46.6%, 67.4%, 64.7%, 49.0%, and 54.4%, respectively. The minimum inhibitory concentration against each fungus was determined using varying concentrations of CFS in potato dextrose agar medium, followed by a regression analysis of mycelial growth inhibition. Except for A. linariae, the logarithmic model provided the best fit in all cases. Tomato seedlings from seeds treated with 10× CFS in inoculated substrate exhibited a survival rate 57% higher than that exhibited by the control treatment. However, no growth promotion was observed in tomato plants from seeds treated with LABIM40 cells or its CFS metabolites. In summary, these findings highlight the antagonistic activity of B. velezensis LABIM40 against A. linariae, B. squamosa, C. lindemuthianum, G. zeae, and R. solani, as demonstrated by dual culture and CFS diffusion tests. This suggests its potential as a biocontrol agent for damping-off in tomatoes

The use of controlled atmosphere with low level of oxygen maintains the quality of guava fruit (Psidium guajaba l. cv. ‘Pedro Sato’) during cold storage

POR] O efeito da atmosfera de armazenamento com diferentes concentrações de oxigênio (controle, 20%, 15%, 10%, 5% e 1%) foi investigado durante o armazenamento refrigerado de goiabas ‘Pedro Sato’. As atmosferas com as menores concentrações de O2 (5% e 1%) reduziram significativamente a taxa respiratória o que resultou no retardamento do proceso de amadurecimento, o que foi confirmado pela manutenção da coloração mais verde (°h), maiores teores de açúcares solúveis totais e redutores, bem como, menor solubilização dos compostos pécticos. Os frutos controle e os armazenados nas maiores concentrações de oxigênio (20% e 15%) apresentaram pico climatérico no 16o e 20o, respectivamente. Entretanto, este não foi observado para os mantidos nas atmosferas contendo 10%, 5% e 1%. Além dos aspectos fisiológicos, as atmosferas com as menores concentrações de O2 (5% e 1%) reduziram o desenvolvimento de podridões o que resultou na manutenção da aparência de conseqüentemente da qualidade final do produto após 28 dias de armazenamento a 12,5°C. [ENG] The effect of storage atmospheres containing different oxygen levels (control, 20%, 15%, 10%, 5% e 1%) was investigated during the cold storage of ‘Pedro Sato’ guava. Atmospheres with the lowest O2 concentrations (5% and 1%) significantly reduced the respiratory rates which delayed the ripening process, which was confirmed by the maintenance of greener colour (°h), higher total soluble and reducing sugar contends, as well as, lower pectic compound solubilization. Control fruit and those stored at the highest oxygen concentration (20% and 15%) presented climateric pick at the 16th and 20th day, respectively. It was not observed for fruit maintained at atmospheres containing 10%, 5% and 1%, although. Despite the physiological aspects, the atmospheres with the lowest O2 concentrations (5% and 1%) reduced rot development leading better appearance maintenance and consequently better final product quality after 28 days of storage at 12.5°C.Os autores gostariam de agradecer a Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) pela concessão da bolsa de pós-doutorado (Proc. no 05/56160-0) e do auxílio à pesquisa (Proc. no 05/56159-1)