Production of bacterial cellulose biopolymers in media containing rice and corn hydrolysate as carbon sources

Bacterial cellulose (BC) is a promising option for ecologically viable processes. In this work, BC was produced using starch hydrolysate (rice and corn flakes) as carbon sources. The starch was hydrolyzed by fungus for glucose production. A maximum yield of 2.80 ± 0.43 g/L of BC was obtained with the hydrolyzed rice medium. Moreover, BC produced in the rice and corn media had crystallinity of around 50%. Fourier-transform infrared spectrometry confirmed the functional groups in BC as well as the absence of contaminants from production process. The thermogravimetric analysis revealed that the polymers formed with alternative media had greater thermal stability. Scanning electron microscopy revealed a morphological structure with the random arrangement of nanofibrils in a non-uniform manner distributed in the weave of both polymeric films. The biofilms produced in different media had similar properties to those of films obtained with a conventional medium, revealing that the polymeric characteristics are not modified.

PROSPECTS FOR IMPROVING THE RECIPE COMPOSITION OF GRAIN BARS AND MARKET ANALYSIS

The market for gluten-free cereal bars as food concentrates and promising food products was studied from the focus of their dietary properties and a functional purpose. The range of grain bars made up 12% of the total food concentrates market in Ukraine and only about 1% of which was devoted to gluten-free grain bars. The main component of both domestic and foreign grain bars included the various products of grain processing. The range of grain bars of domestic and foreign production was analyzed in terms of their component composition and positioning on the market, and then classified into four groups: bars enriched with vitamins; bars with added flavorings and preservatives; bars with sugar substitutes popular among domestic producers; bars with the addition of palm oil, typical for export products. The grain bars of Ukrainian producers were characterized by addition of flax, chia, amaranth, pumpkin, hemp processed products into the composition of gluten bars, but in small quantities. The addition of dried fruits and berries, such as cherries, cranberries, apricots, and grapes, was also popular among domestic manufacturers. Overwhelming majority of the domestic producers used a mixture of four types of cereal flakes as the grain base, namely: oat, wheat, barley and, corn flakes. Taking into account a need in alternative plant resources for the wholesome bars, sorghum, amaranth, flax grain processed products are excellent for the development of gluten-free products. Effect of these non-traditional raw materials (pop sorghum, pop amaranth, flax meal, walnut cake, etc.) on the quality of the grain bars was studied. The use of these ingredients contributed to the enrichment of the grain bars with essential macro-and microelements, lysine, polyphenols, lignin, and vitamins. The developed gluten-free grain bars showed the high consumer qualities; therefore, they are capable to meet the growing demand for gluten-free food products among consumers, providing to widen the range of the grain bars on the Ukrainian market.

Development and optimization of flaked breakfast cereal processing parameters and formulation, incorporated with banana pulp and peel, using response surface methodology

Breakfast cereal plays an important role in a balanced diet. In Malaysia, tons of highly nutritious banana peels, overripe, oversupplied and rejected bananas end up in food waste, as a result of high production and consumption of banana. Thus, this study aimed to produce flaked breakfast cereal with banana pulp, banana peel and cornmeal through oven -baking. Baking temperature, baking time and volume of banana pulp and peel mixture were optimized by using response surface methodology (RSM) to achieve desired fracturability and yellowness. Through this study, fracturability (R2 = 0.98, P≤0.05) and yellowness (R2 = 0.99, P≤0.05) were found to be significantly related to the processing parameters and formulation of the flakes. The optimum processing parameters and formula obtained from this study were the baking temperature of 129.5°C, baking time of 15 mins and volume of banana pulp and peel mixture of 140 g. Besides, a sensory evaluation was conducted and compared among the optimized flakes and commercial corn flakes. Based on the results, there was a significant difference (P≤0.05) in aroma, appearance and taste but no significant difference (P>0.05) in mouthfeel and overall acceptability between both types of flakes. It was recommended that the shelf-life study of the optimized flakes could be done for future study.

Survival and Virulence of Listeria monocytogenes during Storage on Chocolate Liquor, Corn Flakes, and Dry-Roasted Shelled Pistachios at 4 and 23°C

ABSTRACT The survival and virulence of Listeria monocytogenes was assessed during storage on three low-moisture foods (LMFs): chocolate liquor, corn flakes, and shelled, dry-roasted pistachios (water activity [aw] of 0.18, 0.27, and 0.20, respectively). The LMFs were inoculated with a four-strain cocktail of L. monocytogenes at 8 log CFU/g, dried, held until the aw stabilized, and then stored at 4°C and 25 to 81% relative humidity (RH) and at 23°C and 30 to 35% RH for at least 336 days. At 4°C, L. monocytogenes remained stable on the LMFs for at least 336 days. At 23°C, L. monocytogenes levels declined on the chocolate liquor, corn flakes, and pistachios at initial rates of 0.84, 0.88, and 0.32 log CFU/g/month, respectively. After 8 months at 23°C, L. monocytogenes levels on the chocolate liquor and corn flakes decreased to below the limit of detection (i.e., 0.48 log CFU/g). Relative populations of each strain were assessed before storage (i.e., day 0) and after 6 and 12 months of storage at 23 and 4°C, respectively. Generally, a decline in the relative level of the serotype 1/2a strain was observed during storage, coupled with the relative increase in other strains, depending on the LMF and storage temperature. The total viable populations of L. monocytogenes determined by the PMAxx quantitative PCR method after >12 months of storage at 4°C were significantly (1.8- to 3.7-log) higher than those obtained by plating on tryptic soy agar with yeast extract. Decreases in the culturable population of L. monocytogenes during storage on the LMFs were the result of both cellular inactivation and transition to a viable-but-nonculturable state. The surviving cells, specifically after long-term storage at 4°C on the chocolate liquor and pistachios, remained infectious and capable of intracellular replication in Caco-2 enterocytes. These results are relevant for predictive modeling used in microbial health risk assessments and support the addition of LMFs to food safety questionnaires conducted during listeriosis outbreaks. HIGHLIGHTS

MODES OF PRODUCTION SMALL CORN FLAKES IN SEMI-INDUSTRIAL CONDITIONS

The article presents study results of steaming and tempering modes effect on the yield and quality of small corn flakes. Production of small corn flakes was carried out in semi-production conditions on the basis of a test section of the existing machinebuilding operation OLIS Llc, which allowed to get as close as possible to the production conditions. The study consisted of 2 series of experiments: in the first series of experiments, five identical samples of corn grit with an initial moisture content of 13.1% were sent to the steaming stage, where it was subjected to water-heat treatment for a specified period of time (2.5; 5; 7.5, 10 and 12.5 minutes), with increasing steaming time, the tempering time gradually increased by 10 minutes, from 10 to 50 minutes, respectively. In the second series of experiments, the grit was moistened by cold conditioning to a predetermined moisture content of 16±0.25%, moistened for 12 hours, and then moistened grit was subjected to water-heat treatment at the same parameters as in the first series. The initial sample of corn grit No. 4 was obtained in the factory and had the following quality indicators: moisture content – 13.1%; ash content – 0.58%; the starch content – 71.1%. The technological scheme of small corn flakes production in semi-production conditions included the following steps: grit moistening by a special device that sprays water for 15-20 seconds, and wetting in special sealed containers of grit samples (if necessary); grit steaming in the steamer camera of periodic action of EPP-1; tempering for 10-50 minutes in thermostable conditions; flattening of the obtained product on a rolling mill "EVV-1" with smooth rollers at a gap of 0.3-0.4 mm; drying the flattened product on a laboratory dryer; control on the laboratory dispenser RLU-1 (sieving on a sieve No. 067) for extraction of flour products. It was found that as a result of grit steaming with initial moisture content (13.1%) and subsequent flattening in semiproduction conditions a lot of meal was formed – 33.6 and 23.3% with the duration of steaming for 2.5 and 12.5 minutes, respectively, with an ash content of 0.64-0.57% and a starch content of 63.2-63.4%. With the ash content of the original grit of 0.63% and the starch content of 71.1%, it indicated that although moisture penetrated into the inner layers of the grit during conditioning, yet it was not enough on the surface. Therefore, high-ash peripheral grit particles were worse exposed to flattening, crushed and formed meal. Thus, the selected modes of small corn flakes production in semi-production conditions were not sufficient to provide the grit particle with the necessary structural and mechanical changes, and further increase in the duration of processing was impractical, as it significantly increased energy consumption and reduced flakes production productivity. Preliminary wetting of grit to a moisture content of 16±0.25% and subsequent steaming at the same parameters as grit flakes with a starting moisture content of 13.1% showed a significant decrease of flour products output, which amounted to 13.7-7.8% at 2.5 and 12.5 min of steaming, respectively. However, the additional grit moistening before steaming led to an increase in flakes moisture content, which requires higher energy consumption during their drying and bringing them to standards (less than 13.0%), guaranteeing their storage for 6-9 months. The technologically appropriate wet-heat processing mode of corn grit in the production process of flakes in semi-production conditions, to obtain small corn flakes according to the scheme of preliminary wetting of grit, steaming it in a steamer of periodic action, short-term tempering, flattening, drying and control of flakes on meal separation, is a grit moisture content before steaming at 16±2.5%, steaming at atmospheric conditions for 7.5-10 min, duration of tempering – 30-40 min. The obtained flakes do not require cooking, but can be brewed in boiling water for 4-5 minutes.

Functional food as a way to improve nutrition and develop tourism

The aim of this paper is to describe the characteristics of functional products based on cereals and their consumption in the market and tourism, in order to achieve the correlation between food, nutrition and health. All this serves the purpose of building the concept of functional food. This paper presents various technological processes utilized to obtain functional products based on cereals, such as pasta, bread and corn flakes enriched with nutrients (unsaturated fatty acids, mineral elements), probiotics and antioxidants. This paper presents the characteristics of new cereal functional products and different ways to list ingredients. Special emphasis is put on customer reception in the market as a key factor for the successful positioning of a new product.