A Novel Process for the Recovery of Betalains from Unsold Red Beets by Low-Temperature Enzyme-Assisted Extraction

Food waste management plays a central role in the circular economy. To our knowledge, only a few studies have investigated the use of unsold fruit and vegetables from supermarkets as a substitute source for the extraction of natural colorants. Thus, the aim of this paper was to suggest a green, tailored protocol that avoids the use of organic solvents for the recovery of betalains from unsold red beets for use as a food colorant. The recovery of such pigments was carried out by a tailored enzymatic mix, blended considering the polysaccharide composition of the beetroot cell wall; thus, it consisted of: cellulase (37%), xylanase (35%), and pectinase (28%). The enzyme-assisted extraction protocol was optimized, and the most suitable conditions (in terms of pigment yield and color attributes) for the recovery of betalains from unsold beets appeared to be: 25 U/g total dose of enzymatic mix, temperature 25 °C, and processing time 240 min.

Improvement of Agglomeration Technology by a Sinter Mix Preheating

A series of industrial experiments was carried out on the sinter machine No. 1 of the sinter department of JSC "Ural Steel". The dynamics of the sinter mix temperature during the technological stages of its preparation from pelleting to loading on pallets was studied, depending on a water temperature change during pelletizing. It was defined that for the winter working of the sinter department of JSC "Ural Steel" the water temperature increases, which supplied the pelletizer to moistening, for every 10 ° C, facilitates an increase in the temperature of the sinter mix on the pallets by 1.5-2.0 °C. Therefore, for stable sinter mix production with a temperature of more than 55 ° C, it is necessary to use water supplied to the pelletizer for moistening, with a temperature of at least 85°C. To implement the proposed technology, it is necessary to equip the sinter machines with water-heating recuperative heater, installed above the sintering machine behind the ignition hood and using heat, radiated from the surface of the sinter.

Application and Research on Warm Mix Asphalt in China

Environment protection and sustainable development are recognized to be more and more important in the construction of road engineering. For this reason, a new kind of mixture-warm mix asphalt (WMA) is put forward，whose mix temperature lies between hot mix asphalt (HMA) and cold mix asphalt (CMA). Moreover, WMA may be compact in lower temperature without sacrificing performance. The review is focused on research and application of warm mix asphalt in China. And a few problems in application of warm mix asphalt are stated.

Changes in Populations of Listeria monocytogenes Inoculated on Packaged Fresh-Cut Vegetables

A variety of Wholesale and retail packaged vegetables and salads were inoculated with a mixture of strains of Listeria monocytogenes and incubated at 4 and 10°C. Whole rutabagas, butternut squash, and onions, as well as packaged Caesar salad, carrots, coleslaw mix, and stir-fry vegetables were purchased from local supermarkets in the Ottawa area. L. monocytogenes population levels remained constant on all fresh-cut vegetables stored at 4°C for 9 days, except for carrots and butternut squash: counts of cell numbers declined on carrots and increased on the butternut squash. Fresh-cut vegetables stored at 10°C, however, supported good growth of L. monocytogenes on all vegetables tested, except for chopped carrots, where the population decreased approximately 2 log units over a 9-day storage period. As in the situation with the produce stored at 4°C, butternut squash supported the highest rate of cell growth. In addition, Caesar salad and coleslaw mix were kept at 25°C for 1 or 2 days before subsequent storage at 4 or 10°C to simulate extreme temperature-abuse conditions. In Caesar salad stored at 4°C, by day 6 an initial 24- and 48-h temperature abuse at 25°C led to a 1.21- and 2.55-log-unit population increase, respectively, over the control. Similar increases were observed on Caesar salads stored at 10°C. Compared to Caesar salad, coleslaw mix temperature-abused at 25°C and then stored at 4°C supported slightly greater increases in the population of L. monocytogenes, i.e., a 3.22- and 3.83-log-unit increase over the control for the 1- and 2-day abused samples, respectively. Coleslaw mix samples temperature-abused and then stored at 10°C, however, only showed log unit increases of 1.75 and 1.94, respectively, compared to the Controls. These results point to the importance of strict temperature control to prevent or reduce the growth of L. monocytogenes cells on fresh-cut vegetables.