Spotting of Volatile Signatures through GC-MS Analysis of Bacterial and Fungal Infections in Stored Potatoes (Solanum tuberosum L.).

Potatoes inoculated with Pectobacterium carotovorum spp., Aspergillus flavus and Aspergillus niger, along with healthy (control) samples, were stored at different storage temperatures (4 ± 1 °C, 8 ± 1 °C, 25 ± 1 °C) for three weeks. Volatile organic compounds (VOCs) were mapped using the headspace gas analysis through solid phase micro extraction-gas chromatography-mass spectroscopy every week. The VOC data were arranged into different groups and classified using principal component analysis (PCA) and partial least square discriminant analysis (PLS-DA) models. Based on a variable importance in projection (VIP) score > 2 and the heat map, prominent VOCs were identified as 1-butanol and 1-hexanol, which can act as biomarkers for Pectobacter related bacterial spoilage during storage of potatoes in different conditions. Meanwhile, hexadecanoic acid and acetic acid were signature VOCs for A. flavus, and hexadecane, undecane, tetracosane, octadecanoic acid, tridecene and undecene were associated with A. niger. The PLS-DA model performed better at classifying the VOCs of the three different species of infection and the control sample compared to PCA, with high values of R2 (96-99%) and Q2 (0.18-0.65). The model was also found to be reliable for predictability during random permutation test-based validation. This approach can be adopted for fast and accurate diagnosis of pathogenic invasion of potatoes during storage.

Gaseous ozone treatment of chickpea grains: Effect on functional groups, thermal behavior, pasting properties, morphological features, and phytochemicals.

The applicability of ozone has been increased to include pulse grains because of their increased production and significance as plant-based protein source. In many developed countries, there is a growing demand for products made from chickpeas grains. Whole chickpea grains were treated with ozone gas (500-1000 ppm) for 20-30 min. The structural, thermal, pasting properties, and phytochemicals of the ozone-treated, as well as control samples, were evaluated. Minor structural changes in the functional groups in the protein and starch molecules were observed in the treated sample. Ozonation caused significant changes in the pasting properties such as peak viscosity, trough viscosity, breakdown viscosity, final viscosity, setback viscosity, and peak temperature values. Microstructure revealed a reduction in the particle sizes of chickpea powders with the severity of ozone treatment. The total flavonoids (41.35-48.94 mg QE), alkaloids (1120.24-1453.57µg/g), and xanthoprotein (0.995-1.387 µg/g) increased significantly (p < 0.05) with ozone treatment. Commercially, chickpea grains can be ozone treated for achieving desired functional characteristics in a target product. PRACTICAL APPLICATION: Before consuming grain that has been treated with gaseous ozone, it is vitally important for all consumers to have a solid understanding of the facts presented here regarding variations in the chickpea nutritional profile. The impact of ozone treatment on functional groups, thermal behavior, pasting properties, and morphological features in chickpeas reveals vital information regarding changes occurred on macromolecules such as starch, proteins, and bioactive compounds. Since ozonation aids in extraction of health-beneficial bioactive compounds and brings about change in the starch and protein morphology, making them more digestible, it can be highly useful in preparation of health foods.

Gaseous ozone treatment of chickpea grains, part I: Effect on protein, amino acid, fatty acid, mineral content, and microstructure.

The effect of gaseous ozone (500-1000 ppm) treatment on the protein, amino acid, and fatty acid profiles, mineral content, and the microstructure of the chickpea grains were evaluated. Though protein content was not altered significantly, SDS PAGE profiling exhibited minor modifications in the protein bands of the treated chickpea. The essential amino acids (EAA) and total amino acids (TAA) slightly decreased, ratio of EAA to TAA increased, while the calculated protein efficiency ratio decreased. Significant decrease in the SH content and non-significant increase in SS content was observed at higher doses of ozone. The overall saturated and unsaturated fatty acids (%) were in the range of 13.05-13.49 and 86.51-87.61, respectively. The minerals were stable and the HCl extractability decreased in the ozonated samples. There was some minor degradation of intracellular cell wall and distribution of starch and protein bodies in the ozonated sample.

Development of microencapsulated anthocyanin-rich powder using soy protein isolate, jackfruit seed starch and an emulsifier (NBRE-15) as encapsulating materials.

A trend of present encapsulation research indicates an increased interest in the search for natural encapsulants for bioactive phytochemicals. The present study in pursuit of the same studies the use of jackfruit seed starch (JSS), an underutilized natural polysaccharide in conjugation with soy protein isolate (SPI) as an encapsulating material and NBRE-15 as an emulsifier. Three independent variables viz., total soluble solids (TSS, 20, 25 and 30° Brix), SPI: JSS (1:1, 1:3 and 1:5) and NBRE-15 (0.1, 0.2 and 0.3%) were optimized for achieving the most efficient encapsulation of anthocyanin using a three level, three parameter, Box-Behnken design (BBD) of the Design of Experiments (DOE). The responses considered for the optimization were monomeric anthocyanin content, antioxidant activity and encapsulation efficiency. A combination of 27.0% TSS, 1:5 SPI: JSS ratio and 0.3% NBRE-15 was found to be optimum for the encapsulation of anthocyanin with the desirability of 92.6%. Microcapsules obtained using the optimized combination of independent variables was found to contain 3215.59 mg/100 g monomeric anthocyanin. The antioxidant activity and encapsulation efficiency of the encapsulated material obtained using optimized combinations of independent variable were found to be 365.26 µmol Trolox/g and 89.71%, respectively. The microcapsules were also additionally analyzed for the particle size distribution and morphological characterization. Particle size analysis indicated that the microcapsules obtained had a mean particle size of 60.97 µm. Scanning electron microscopy for morphological characterization indicated that the microcapsules so obtained were oval to round in shape and had a smooth surface. Storage studies to estimate the half-life of anthocyanin in the microcapsule at room temperature (37 °C) clearly indicated greater stability i.e. 63 days when stored under amber-colored vial compared to only 35 days when stored under clear transparent vial.

Effect of different processing conditions on proximate composition, anti-oxidants, anti-nutrients and amino acid profile of grain sorghum.

The effect of different processing conditions (B: boiling; F: LAB fermentation; FS: fermentation and steaming; FSF: fermentation, steaming, flaking) of whole grain sorghum on the proximate composition, antioxidants, anti-nutrients, and amino acids (AAs) was evaluated. A marginal increase in the protein content and a decrease in the fat content was observed in the F-sample. Total phenolics reduced by 28%; DPPH scavenging activity and CUPRAC activity increased by 1.4 and 6 times, respectively during fermentation. Tannin content reduced by 30-39%, for the F, FS and FSF samples; highest reduction in trypsin inhibitory activity (58%) was observed in the FS-sample. Total AAs increased by 2.9 folds in FSF samples. Grain sorghum contained mostly hydrophobic AAs (30-34%). The ratio of Essential amino acid to total amino acid and predicted protein efficiency ratio were highest in the F-sample, whereas predicted biological value of the FSF was 3 times than that of the control.

Optimization of pretreatments and process parameters for sorghum popping in microwave oven using response surface methodology.

Sorghum is a popular healthy snack food. Popped sorghum was prepared in a domestic microwave oven. A 3 factor 3 level Box and Behneken design was used to optimize the pretreatment conditions. Grains were preconditioned to 12-20 % moisture content by the addition of 0-2 % salt solutions. Oil was applied (0-10 % w/w) to the preconditioned grains. Optimization of the pretreatments was based on popping yield, volume expansion ratio, and sensory score. The optimized condition was found at 16.62 % (wb), 0.55 % salt and 10 % oil with popping yield of 82.228 %, volume expansion ratio of 14.564 and overall acceptability of 8.495. Further, the microwave process parameters were optimized using a 2 factor 3 level design having microwave power density ranging from 9 to 18 W/g and residence time ranging from 100 to 180 s. For the production of superior quality pop sorghum, the optimized microwave process parameters were microwave power density of 18 Wg(-1) and residence time of 140 s.

Encapsulation of black carrot juice using spray and freeze drying.

Black carrot juice extracted using pectinase enzyme was encapsulated in three different carrier materials (maltodextrin 20DE, gum arabic and tapioca starch) using spray drying at four inlet temperatures (150, 175, 200 and 225 ℃) and freeze drying at a constant temperature of - 53 ℃ and vacuum of 0.22-0.11 mbar with the constant feed mixture. The products were analyzed for total anthocyanin content, antioxidant activity, water solubility index, encapsulation efficiency and total colour change. For both the drying methods followed in this study, maltodextrin 20DE as the carrier material has proven to be better in retaining maximum anthocyanin and antioxidant activity compared to gum arabic and tapioca starch. The best spray dried product, was obtained at 150 ℃. The most acceptable was the freeze dried product with maximum anthocyanin content, antioxidant activity, water solubility index, encapsulation efficiency and colour change.

Postharvest hardness and color evolution of white button mushrooms (Agaricus bisporus).

UNLABELLED: The quality evaluation of mushrooms was studied by storing fresh white button mushrooms (Agaricus bisporus) for 6 to 8 d, at various controlled temperature conditions (3.5 to 15 degrees C) and measuring the instrumental textural hardness and color of the mushroom cap for different product batches. A nonlinear mixed effect Weibull model was used to describe mushroom cap texture and color kinetics during storage considering the batch variability into account. Storage temperature was found to play a significant role in controlling texture and color degradation. On lowering storage temperature (i) the extent of the final browning extent in the mushroom after storage was reduced and (ii) the rate textural hardness losses was slowed down. A linear dependence of the final browning index with temperature was found. An Arrhenius type relationship was found to exist between the temperature of storage and storage time with respect to textural hardness. The average batch energy of activation was calculated to be 207 +/- 42 kJ/mol in a temperature range of 3.5 to 20 degrees C. PRACTICAL APPLICATION: This article evaluates how temperature abuse affects mushroom texture and color, applying methods that allow for the consideration of the natural product variability that is inherent in mushrooms. Its results apply to mushroom producers, retail distribution, and supermarkets for effective storage management.