Food and Bioproducts Processing最新文献

Microbial polysaccharides have been gaining growing interest often as alternative to animal derived products or as sources of novel features for biotechnological applications. Process production costs, however, are still high. A possible solution to that exploits agri-food and dairy industrial byproducts as fermentation substrates. This approach also reduces the need for cost-intensive disposal treatments for these waste sources and supports green and circular economy policies. Therefore, as for other microbial glucuronic acid-based biopolymers (e.g. hyaluronic acid, alginate), in this perspective, wild type and engineered E. coli K4 were used in this work as cell factories to produce K4 capsular polysaccharide (CPS) from renewable sources. The backbone of the K4 CPS, chondroitin, is the precursor of chondroitin sulfate (CS), a glycosaminoglycan found in animal tissues that is extensively used for curing osteoarthritis and studied for several other emerging biomedical applications. Interestingly, also chondroitin showed promising bioactivity in vitro and in vivo. Due to its high availability from local companies, second cheese whey (SCW), a worldwide copious and polluting liquid waste, was used as fermentation substrate in this work. Results showed that SCW fully supports growth of wild type and recombinant E. coli K4 strains, and demonstrate, for the first time up to date, the production of K4 CPS from liquid waste as proof of principle. Batch processes in 3 L fermenters indicated a 100 % improvement of the polysaccharide yield and allowed the production of 1.1±0.1 g/L of product from the recombinant strain with very low accumulation of acetic acid, demonstrating that SCW by itself fully supports polysaccharide production.

Casein is the most abundant protein in milk with good emulsifying properties and bioavailability. However, the tight micellar structure of casein results in poor solubility. In the case of soft solid materials such as processed cheese, imitation cheese, yoghurt and protein-based oil-in-water emulsions, poor solubility directly affects the homogeneity and stability of the texture structure of such products, leading to a poor user experience. In this study, two protein modification techniques, hydrolysis and succinylation, were combined to improve the solubility of casein and the stability of its emulsions. The individual and combined effects of enzymatic hydrolysis and succinylation modification approaches on the stability of rennet casein (RC) and micellar casein (MC) emulsions were further explored. After double-treatment of casein with enzymatic hydrolysis and succinylation, the solubility of RC and MC was up to about 95 %, which was superior to that of single-treatment. Fourier transform infrared spectroscopy showed that the characteristic wave signals of the double-treated samples were located between the two single-treated samples, and that there may be an opposite effect between the two modifications. After 21 days of storage, the emulsions prepared from double-treated caseins still remained stable. The salt ionic stability and freeze-thaw stability were significantly improved, and the physical stability of MC was increased by nearly three times. The results explained the effects of enzymatic hydrolysis and succinylation on the functional properties of casein, provided a reference for the development of food systems based on oil-in-water emulsions, and offered a new idea for the wide application of succinylated casein.

Tenderness is one of the most important criteria in bovine meat, as it determines whether the meat is used for grilling, long-time cooking or post-processing. It is therefore of great interest for the industry to measure it. Common systems require the extraction and destruction of samples, inducing time and material expenses. In this article, a new nondestructive characterization apparatus, based on monitored indentation, relaxation, and recovery, is proposed. Samples from two cuts known for their difference in tenderness were used from the same carcass. Their tenderness were assessed via compression tests and then compared to indicators from the force–displacement measurements. Results showed that the indentation and recovery speed, and the force relaxation enable the differentiation of the two cuts ($p<0.05$). These results were obtained on samples from a single carcass. Measurements on other carcasses should be performed to ensure that the results presented in this article can be generalized to bovine meat.

The search for renewable sources that can be used to develop products as alternatives to traditional polymers in the future, without affecting food safety, represents a challenge for the food industry. In this context, agro-industrial waste has emerged as an interesting alternative. This study evaluated biodegradable films made from Hass avocado seed flour without (Control film; PC) and with antioxidant extracts (PExBIO and PExIND) derived from the epicarp of the same fruit. The results showed that all the films blocked visible (over 96 %) and ultraviolet light (99.9 %), which was mainly attributed to perseorangine, a compound generated by the action of polyphenol-oxidase. The films also exhibited good water vapor barrier properties. PExIND showed the highest mechanical strength (Young's modulus = 901.8 ± 33.4 MPa; tensile strength = 9.1 ± 1.0 MPa; elongation = 3.5 ± 0.5 %), correlating with the highest crystallinity index (14.9 %). The incorporation of extracts increased the content of phenolic compounds and antioxidant capacity in PExBIO and PExIND compared to PC, with no significant differences between them. Moreover, the biodegradation test indicated that the films showed high biodegradability. Therefore, Hass avocado residues could be used to produce biodegradable antioxidant films, suitable for packaging light-sensitive and low-moisture products.

The nutraceutical beverages market has increased in recent years, motivated by the increasing trend of consumers choosing food and beverages beneficial to health, mostly after the COVID-19 pandemic. Several researchers have proposed different formulations, where the combination of plants has been tested at the laboratory and pilot scales to maximize the desirable features of the beverages, including antioxidant capacity, anticarcinogens, and anti-inflammatory properties. Developing these products requires scaling-up from these scales to the industry one and, hence, identifying the criteria and/or parameters affecting process yield due to the transport phenomena associated with the scale increment. This work proposes a framework for scaling up solid-liquid extraction in a nutraceutical beverage process using available pilot plant data, combining brute-force and empirical scaling approaches. This framework provides an alternative for industries that have acquired equipment without considering the principles of similarity between the larger scale and the laboratory stage. Operating conditions are tuned to reach the product quality at the pilot level and the maximum beverage's antioxidant capacity. A techno-economic analysis of the production process and an environmental evaluation were performed, providing the basis for an effective scaling-up to the industry level. The scaling-up proved to be feasible, as the net present value of the process is $2018,000 with a payback time of 4.83 years; the major source of solid waste is the raw materials with a carbon footprint less than 0.205 MT eCO₂ due this process operates with temperatures lower than 100 °C. The circular economy indicators in this project were circular material usage rate and Waste Stream Recycling Rate. The Circular Material Usage Rate ranged from 16.7 % to 66.7 % depending on the composition of the cocoa husk in the raw material, and the Waste Stream Recycling Rate (%) ranged from 4.4 % to 5 % destined for composting development. The framework is designed to be applicable to other food production processes that encounter equipment constraints. It facilitates the evaluation of process yield and enables the simulation and analysis of economic profitability and environmental impact using circular economy indicators at an industrial/commercial scale.

Brewers’ spent grain (BSG), the solid waste of the brewing industry, is high in fibres, proteins and health-beneficial compounds such as polyphenols. This research investigated bioprocessing with enzymes and microbes to modify the properties of BSG for its utilisation as a food ingredient. Pre-treatment studies showed that wet milling performed better than dry milling, and heat and homogenisation either before or after the enzyme hydrolysis did not significantly influence the release of reducing sugars and free amino nitrogen (FAN). Four treatments were applied to wet-milled BSG: fermentation with Lactiplantibacillus plantarum POM1 with or without the enzyme Ondea pro and enzymatic bioprocessing without any fermentation. Control was the condition without enzyme and starter. Without the enzyme, there was negligible free sugar and FAN, and the starter had limited growth and organic acid production. Only the combination of enzymatic hydrolysis and fermentation reached a pH of 4 and 10 mg/g DW lactic acid. The microbial preference for monosaccharides was evident, and the enzyme influenced the release of oligosaccharides that can have a prebiotic effect. Bioprocessing impacted the phenolic acid composition and microbial consumption, with a significant release of ferulic acid during enzyme hydrolysis.