Effects of preheating and drying methods on pyridoxine, phenolic compounds, ginkgolic acids, and antioxidant capacity of Ginkgo biloba nuts.

Although ginkgo nuts are very nutritious and loaded with numerous bioactive compounds, the nuts contain significant levels of unwanted compounds (ginkolic acids) which are toxic to consumption. To reduce or eliminate these toxic compounds without impacting the nutritional value and the bioactivity of the final product, an appropriate processing technology is needed. Thus, the effect of preheating (90 and 120°C) prior to drying (freeze drying: FD, hot air drying: HAD, and HAD in tandem with FD: HAD-FD) was evaluated on ginkgolic acids, pyridoxine analogues, phenolic compounds, and antioxidant properties of ginkgo nuts. Our results pointed out a significant decrease (below 50%) of ginkgolic acids in ginkgo nuts samples processed at 90°C compared to the control. The major compounds found after treatments were respectively, kaempferol (36.66-354.38 µg/g), quercetin (9.04-183.71 µg/g), and caffeic acid (19.66-106.88 µg/g). Principal component analysis (PCA) revealed that preheating at 90°C prior to HAD-FD would be a proper and reasonable approach for preserving the bioactive compounds and antioxidant capacity of ginkgo nuts (EC50 ranged from 2.25 to 4.60 mg/mL) while significantly reducing their content in toxic compounds.

Effect of Chinese chives (Allium tuberosum) addition to carboxymethyl cellulose based food packaging films.

Carboxymethyl cellulose (CMC) based novel functional films containing Chinese chives root extract (CRE) at different concentrations (1, 3 and 5 % in w/w) were successfully fabricated. It was revealed by SEM that higher extract concentration triggered the formation of agglomerates within the film. Tensile strength of the films was decreased from 30.91 to 16.48 MPa. Thickness of films was increased from 43 to 84 µm, while decrease in water solubility from 77.51-52.91 %, swelling degree from 55.74 to 40.37 %, and water vapor permeability from 5.76 to 1.17 10-10 gm-1s-1 Pa-1 was observed. DPPH and ABTS radical scavenging ability of CMC-CRE films was increased from 0 to 58 % and 82 %, respectively. CMC-CRE5 film showed the highest biodegradability of 58.14 %. The film prepared by the addition of CRE into CMC also exhibited good antioxidant and antimicrobial activity indicating that it could be developed as a bio-composite food packaging material for the food industry.

Chitosan-based biodegradable active food packaging film containing Chinese chive (Allium tuberosum) root extract for food application.

The objective of the present study was to develop chitosan (CS) based novel functional films containing Chinese chive root extract (CRE) using solution casting method. CRE at different concentrations (1, 3 and 5% in w/w) were incorporated into the film-forming solution. Scanning electron microscopy (SEM), Fourier transform-infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and thermal behavior analysis (DSC & TGA) were performed to investigate the structure, potential interaction and thermal stability of prepared films. It was revealed by SEM that higher extract concentration triggered the formation of agglomerates within the films. Incorporation of CRE into CS resulted in decrease tensile properties of the films from 28.9 to 15.4 MPa, whereas thickness was increased from 0.076 to 0.113 mm. The water solubility, swelling degree and water vapor permeability were significantly decreased from 31.6 to 18.7%, 57.4 to 40.5% and 15.67 to 7.81 × 10-11 g·m-1s-1Pa-1, respectively. DPPH and ABTS radical scavenging ability of CS-CRE films were increased from 6.95 to 47.05% and 11.98 to 57.38%, respectively. CS-CRE5 film showed the highest biodegradability of 47.36%. The films prepared by addition of CRE into CS exhibited good antioxidant and antimicrobial activity indicating that it could be developed as bio-composite food packaging material for food industry.

A comparative evaluation of nutritional properties, antioxidant capacity and physical characteristics of cabbage (Brassica oleracea var. Capitate var L.) subjected to different drying methods.

Cabbag has been considered as one of attractive raw materials for dehydrated vegetables owing to high nutrient value. However, information about how drying methods affect the physicochemical properties of cabbage is limited. In present study, segmented cabbages were subjected to freeze drying (FD), hot air drying (HAD), microwave vacuum drying (MVD), vacuum drying (VD), MVD combined with HAD (MVD + HAD) and VD (MVD + VD). Dehydrated cabbages were compared in terms of nutritional components, antioxidant activity, microstructure, texture and so on. Results demonstrated that HAD conducted a worse effect, with loss rate of nutritional components >45%. However, two combined methods performed higher retention for nutritional compositions, better antioxidant activity and lower energy consumption than individual HAD. Furthermore, MVD + HAD products exhibited higher rehydration capacity and more uniform honeycomb porous structure but lower hardness compared to HAD. This conclusion would be fundamental for choosing more appropriate drying methods to obtain desirable quality.

Effects of ultrasound and chemical treatments on white mushroom (Agaricus bisporus) prior to modified atmosphere packaging in extending shelf-life.

Effects of pre-treatments of white mushrooms prior to modified atmosphere packaging on their physico-chemical and microbiological properties were studied during 12 days of storage at 4 °C. Physico-chemical and microbiological properties of differently treated mushrooms stored at 4 °C were significantly different (P < 0.05) from untreated ones. Washed samples exhibited the smallest respiration rate compared to all other samples. Hydrogen peroxide washing was effective in retaining mushrooms colour change. Furthermore, the diminishments in weight of ultrasound treated samples during storage were significantly (P < 0.05) low in comparison with the other four treatments. The weight loss for ultrasound treated samples were 3.52 %, 4.07 % and 4.59 % for Uca, UH2O2 and UH2O respectively. The lowest PPO activity was observed in Uca, UH2O2 followed by Wca, WH2O2, UH2O and WH2O treatments respectfully. Combined treatments showed lower polyphenol oxidase activity, retained antioxidants, delayed pseudomonas growth and did not cause any decline in tissue firmness during storage time implying that it could extend shelf life of white mushrooms up to 12 days at 4 °C.

Separation and characterization of dextran extracted from deteriorated sugarcane.

In this research work, dextran was extracted from deteriorated sugarcane by alcohol precipitation and purified by gel filtration chromatography. Total acid hydrolysis and enzymatic degradation were utilized to confirm the purity of separated polysaccharide. Using the more recently available techniques such as ((1)H,(13)C) and two-dimensional (COSY and HMQC) NMR spectral analysis, methylation GC-MS and MALDI-TOF mass spectrometry, the structure of sugarcane dextran (SC-Dex) was investigated. On the basis of all spectra, SC-Dex showed a branched polysaccharide that contained only d-glucose residues in consecutive α-(1-6) linkages in the main chain with α-(1-3) branches. Methylation analysis showed that, the degree of α-(1-3) branching levels was 4.37%. Several structural fragments were identified from MALDI-TOF spectrum with peak-to-peak mass difference of 162gmol(-1), which confirmed that the repeat unit in SC-Dex was d-glucose. The surface morphology of SC-Dex, revealed the spherically shaped and porous structure. Using HPSEC-MALLS-RI system, the average molecular weight of SC-Dex was estimated to be 1.753×10(6)gmol(-1) with an index of polydispersity value of 1.069.