A new method for the production of compote from grapes in self-exgaustible glass jars 1-82-500

Проблема повышения пищевой ценности консервируемых пищевых продуктов в герметически укупоренной таре может быть успешно решена на основе интенсификации процесса тепловой стерилизации. В работе представлены результаты исследований по совершенствованию технологии производства консервированного компота из винограда с использованием самоэксгаустируемой тары и интенсификации процесса тепловой стерилизации, являющейся наиболее широко используемым методом консервирования пищевых продуктов, совершенство которой во многом определяет пищевую ценность готового продукта. Известно, что продолжительность и температурный уровень стерилизационного процесса существенно могут изменить качественный и количественный состав витаминов, белков, углеводов, минеральных и органических кислот и других веществ, что зачастую приводит к снижению пищевой ценности продукта. На основе оценки традиционного стерилизационного режима разработаны и предложены новый способ и режимы стерилизации, которые обеспечивают сокращение продолжительности тепловой обработки более чем на 30 % и повышение пищевой ценности готовой продукции. Установлено, что предварительное повышение температуры продукта и использование самоэксгаустируемых стеклобанок обеспечивают сохранение витамина С в готовом продукте на 0,8 мг/% выше, чем по традиционной технологии. Полученные результаты представляют интерес для реализации на предприятиях по переработке растительного сырья. The problem of increasing the nutritional value of canned food products in hermetically sealed containers can be successfully solved by intensifying the process of thermal sterilization. The paper presents the results of research on improving the technology of production of canned compote from grapes using self-exgaustible containers and intensifying the process of thermal sterilization, which is the most widely used method of preserving food products and the perfection of which largely determines the nutritional value of the finished product. It is known that the duration and temperature level of the sterilization process can significantly change the qualitative and quantitative composition of vitamins, proteins, carbohydrates, mineral and organic acids and other substances, which often leads to a decrease in the nutritional value of the product. Based on the assessment of the traditional sterilization regime, a new method and modes of sterilization have been developed and proposed, which provide a reduction in the duration of heat treatment by more than 30 % and an increase in the nutritional value of the finished product. It was found that the use of a preliminary increase in the temperature of the product and the use of self-exgaustible glass jars ensures the preservation of vitamin C in the finished product by 0.8 mg/% higher than by traditional technology. The results obtained are of interest for implementation at plants processing plant raw materials.

A Case-study: Temperature Distribution and Heat Penetration in Steam-air Retort, Using Glass Jars and Retort Pouches

Retort thermal sterilization of canned food is a technology, which allows preserving food products by applying heat on packaged food in retorts (autoclaves) at temperatures up to 121 °C. The thermodynamics of the processes in the retort are influenced by the product stacking method in the basket and packaging material. The aims of this study were: 1) to analyse and compare temperature distribution (TD) and the slowest to heat location in the steam-air retort stacked with glass jars and with retort pouches; 2) to analyse and compare commercial product heat penetration (HP) characteristics in glass jars and retort pouches. Temperature measurements were performed with wireless thermocouples. The come-up time (heating phase) required to achieve in the retort temperature uniformity criteria of ±0.5 °C, is 28 min when the retort is stacked with glass jars, and 24 min when the retort is stacked with retort pouches. Total calculated process time (holding phase), necessary to achieve the sterilization value (F0 of 3 min), for sample in glass jars was 67 min, but in retort pouches – 62 min. The overall sterilization process time difference between two considered packaging types was 9 min, which is significant amount of time in the context of commercial processing. The study clearly shows the necessity to perform the Temperature Distribution and Heat Penetration study, as each packaging material, stacking method and product will affect sterilization process thermodynamics and, therefore, the overall process time and consequently - the safety of food product.

High-pressure thermal sterilization and ε-polylysine synergistically inactivates Bacillus subtilis spores by damaging its inner membrane

The study aimed to determine the sterilization effect of a combination of high-pressure thermal sterilization (HPTS) and ε-polylysine (PL) on Bacillus subtilis spores. The spores were treated with HPTS (550 MPa at 25°C, 65°C and 75°C) combining with ε-PL at 0.1% and 0.3%. The results showed that HPTS and ε-PL synergistically inactivated the spores. The increased temperature and ε-PL concentration decreased the number of surviving spores, with the maximal inactivation of the spores in the treatment of 550 MPa, 75°C combining with 0.3% ε-PL. The increases in the temperature and ε-PL concentration significantly increased the release of the intracellular components in the spore suspension, with the maximal value for the spores treated with 550 MPa, 75°C and 0.3% ε-PL. The maximal fluidity and permeability of the cell inner membrane were observed in the treatment of 550 MPa, 75°C combining with 0.3% ε-PL. Changes in membrane lipids were detected from 3000 to 2800 cm -1 by Fourier transform infrared spectroscopy. The results may provide new insights into the mechanism by which HPTS and ε-PL synergistically sterilize Bacillus subtilis spores.

Thermosonication Combined with Natural Antimicrobial Nisin: A Potential Technique Ensuring Microbiological Safety and Improving the Quality Parameters of Orange Juice

Currently, thermal pasteurisation (TP) remains the most widely applied technique for commercial orange juice preservation; however, a high temperature causes adverse effects on the quality attributes of orange juice. In order to explore a novel non-thermal sterilization method for orange juice, the impacts of thermosonication combined with nisin (TSN) and TP treatments on the quality attributes including microbial and enzyme inactivation and the physicochemical, nutritional, functional, and sensory qualities of orange juice were studied. Both TP and TSN treatments achieved desirable bactericidal and enzyme inactivation effects, and nisin had a significant synergistic lethal effect on aerobic bacteria in orange juice (p < 0.05). Additionally, TSN treatment significantly improved the color attributes of orange juice and well maintained its physicochemical properties and sensory quality. More importantly, TSN treatment significantly increased the total polyphenols content (TPC) and total carotenoids (TC) by 10.03% and 20.10%, increased the ORAC and DPPH by 51.10% and 10.58%, and the contents of total flavonoids and ascorbic acid were largely retained. Correlation analysis of antioxidant activity showed that the ORAC and scavenging ability of DPPH radicals of orange juice are mainly attributed to TC and TPC. These findings indicate that TSN shows great potential application value, which could guarantee the microbiological safety and improve the quality attributes of orange juice.