Fe and Zn in vitro bioavailability in relation to antinutritional factors in biofortified beans subjected to different processes.

The present work evaluated the effect of different processes in relation to mineral content and its bioavailability, as well as the effect of phytate and oxalate contents in biofortified beans. The following treatments were evaluated: raw beans (RB), cooked and oven-dried soaked beans (BOS), cooked and freeze-dried soaked beans (BFS), cooked and oven-dried beans without soaking (BOWS) and cooked and freeze-dried beans without soaking (BFWS). The mineral contents (mg per 100 g) varied between 3.56 and 5.80 (iron), 20.26 and 89.32 (calcium) and 1.56 and 2.38 (zinc). The oxalate content varied from 3.74 to 10.54 mg per 100 g. The total phytate content ranged from 1803.23 to 2.301 mg per 100 g. Regarding mineral bioavailability in Caco-2 cells, iron retention ranged from 8.89 to 17.85% and uptake was from 12.07 to 13.74 µg. On the other hand, the zinc retention was from 92.27 to 98.6% and uptake ranged from 24.68 to 36.26 µg. The different forms of bean processing can contribute to the mineral profile of this legume, in addition to increasing the bioavailability of some minerals, such as iron and zinc.

Properties of an amylase from thermophilic Bacillus SP.

α-Amylase production by thermophilic Bacillus sp strain SMIA-2 cultivated in liquid cultures containing soluble starch as a carbon source and supplemented with 0.05% whey protein and 0.2% peptone reached a maximum activity at 32 h, with levels of 37 U/mL. Studies on the amylase characterization revealed that the optimum temperature of this enzyme was 90°C. The enzyme was stable for 1 h at temperatures ranging from 40-50°C while at 90°C, 66% of its maximum activity was lost. However, in the presence of 5 mM CaCl2, the enzyme was stable at 90°C for 30 min and retained about 58% residual activity after 1 h. The optimum pH of the enzyme was found to be 8.5. After incubation of enzyme for 2 h at pH 9.5 and 11.0 was observed a decrease of about 6.3% and 16.5% of its original activity. At pH 6.0 the enzyme lost about 36% of its original activity. The enzyme was strongly inhibited by Co(2+), Cu(2+) and Ba(2+), but less affected by Mg(2+), Na(+) and K(+). In the presence of 2.0 M NaCl, 63% of amylase activity was retained after 2 h incubation at 45°C. The amylase exhibited more than 70% activity when incubated for 1 h at 50°C with sodium dodecyl sulphate. However, very little residual activity was obtained with sodium hypochlorite and with hydrogen peroxide the enzyme was completely inhibited. The compatibility of Bacillus sp SMIA-2 amylase with certain commercial detergents was shown to be good as the enzyme retained 86%, 85% and 75% of its activity after 20 min incubation at 50°C in the presence of the detergent brands Omo(®), Campeiro(®) and Tide(®), respectively.

Ultrasound improves antimicrobial effect of sodium dichloroisocyanurate to reduce Salmonella Typhimurium on purple cabbage.

The consumer's interest in ready-to-eat, fast-ready, nutritious and fresh foods is a major challenge for the food industry. Thus, studies on new sanitization methods are relevant. The effect of Sodium Hypochlorite (SH), Benzalkonium Chloride (BC), and Sodium Dichloroisocyanurate (SD) isolated or combined with Ultrasound (US) in purple cabbage quality over 7 days of storage at 8 ±â€¯1 °C was evaluated. The natural microbiota (mesophilic aerobic bacteria, lactic acid bacteria and coliforms), intentionally inoculated Salmonella Typhimurium, physicochemical quality (anthocyanins, pH, total titratable acidity, instrumental color and mass loss) and sensorial quality (multiple comparison test and visual sensory acceptance) were analyzed. The best treatments for natural microbiota reduction were BC and US + BC, which in general reduced between 1.9 and 3.2 log cfu/g. US improved (p < .05) the effect of SD reducing almost 4 log cycles in the population of S. Typhimurium adhered to cabbage. The treatments with benzalkonium chloride resulted in important physicochemical changes in cabbage. The treatments SD and US + SD did not alter the physicochemical and sensorial characteristics of purple cabbage. Therefore, ultrasound combined with sodium dichloroisocyanurate is a promising alternative for the reduction of microbiological contaminants of purple cabbage without physicochemical, sensory and anthocyanin content loss.

Ultrasound improves chemical reduction of natural contaminant microbiota and Salmonella enterica subsp. enterica on strawberries.

New sanitization methods have been evaluated to improve food safety and food quality and to replace chlorine compounds. However, these new methods can lead to physicochemical and sensory changes in fruits and vegetables. The present study evaluated the effects of acetic acid, peracetic acid, and sodium dodecylbenzenesulfonate isolated or combined with 5min of ultrasound treatment (40kHz, 500W) on strawberry quality over 9days of storage at 8°C. The strawberry natural contaminant microbiota (molds and yeasts, mesophilic aerobic and lactic acid bacteria), physicochemical quality (pH, total titratable acidity, total soluble solids, vitamin C, and color), sensory quality (triangle test) and inactivation of Salmonella enterica subsp. enterica intentionally inoculated onto strawberries were analyzed. Ultrasound increased the effect of all chemical compounds in the reduction of aerobic mesophilic, molds and yeasts. The best treatment for those groups of microorganisms was ultrasound combined with peracetic acid (US+PA) that reduced 1.8 and 2.0logcfu/g during 9days of storage. Bactericidal effect of peracetic acid was also improved by ultrasound inactivation of S. enterica, reaching a decimal reduction of 2.1logcfu/g. Moreover, synergistic effects were observed in contaminant natural microbiota inactivation for all tested compounds during storage, without any major physicochemical or sensory alteration to the strawberries. Therefore, ultrasound treatment can improve the effect of sanitizers that are substitutes of chlorine compounds without altering the quality of strawberries during storage. Acetic acid (PubChem CID: 176); Peracetic acid (PubChem CID: 6585); Sodium dodecylbenzenesulfonate (PubChem CID: 18372154).