Food Technology and Biotechnology最新文献

Research background: Hydrogenated fats are widely used to improve texture, flavor, and shelf life in processed foods, but their excessive consumption contributes to cardiovascular diseases. While Butia seed oil contains saturated fats, its potential as an alternative structuring lipid in food applications remains unexplored. This study investigates the formulation of oleogels based on Butia seed oil and their potential as a replacement for hydrogenated fats in cookies.

Experimental approach: The aim of this study is to develop oleogels based on Butia seed oil and beeswax (w=1, 3 and 5 %) and use them in cookies as a substitute for hydrogenated fat. The chemical composition, thermal properties and functional groups of Butia seed oil and beeswax were analyzed. The lipid stability, oil binding capacity, gel stability, thermal properties and color parameters of the oleogels were characterized. The oleogels were then added to cookies as a substitute for hydrogenated vegetable fat. Mass loss, color, expansion factor, specific volume and texture properties of the cookies were evaluated.

Results and conclusions: Butia seed oil had saturated fatty acids (22.87 mg/mL lauric and 22.45 mg/mL caprylic acid) and notably high concentrations of unsaturated fatty acids (oleic acid 33.21 mg/mL and linoleic acid 30.61 mg/mL). Oleogels containing 3 and 5 % beeswax remained stable for 90 days. Increasing the beeswax mass fraction resulted in greater hardness of the oleogels (p<0.05). Specifically, the oleogel with 5 % beeswax had the highest oil binding capacity, reaching 99.9 %. Cookies formulated with oleogel showed lower hardness and mass loss, as well as a higher specific volume than the control cookie (without oleogel). Notably, the use of oleogels did not alter the visual characteristics of the cookies, supporting their potential as a viable fat replacer in oven-baked products.

Novelty and scientific contribution: These results suggest that oleogels containing Butia seed oil have the potential to replace hydrogenated vegetable fats in food products. This study shows that oleogels with Butia seed oil, particularly with beeswax mass fractions of 3-5 %, can effectively replace hydrogenated vegetable fats in cookie formulations. Unlike traditional structuring fats, these oleogels offer improved lipid profiles while maintaining desirable baking properties.

Research background: Spotted goatfish (Pseudupeneus maculatus) is of significant economic importance on the coast of Pernambuco, Brazil, being relevant in domestic and export markets. The fish is exported in different forms, whole, gutted, and as fillets, generating protein-rich waste. This study aims to produce a protein concentrate from spotted goatfish and add value by developing a nutritious, high-protein snack. In addition, passion fruit peel flour was used to improve the fiber content of the product.

Experimental approach: The snacks were formulated with sour cassava starch, corn meal, condiments, 0 or 5 % spotted goatfish protein concentrate, and 0 or 2 % passion fruit peel flour. The physicochemical, microbiological and sensory properties of the products were compared.

Results and conclusions: The products met microbiological standards for quality and safety. The snacks with added spotted goatfish protein concentrate had higher protein content than the control. Additionally, the use of passion fruit peel flour improved the texture and acceptability of the snack.

Novelty and scientific contribution: The scientific contribution of this study is the improvement of snacks using co-products from the fish and juice industries, resulting in a product with improved nutritional quality in terms of protein and fiber. In addition, the use of agricultural waste supports greater sustainability.

Research background: Recently, extensive use of refined sugars and artificial sweeteners has led to negative health implications. Therefore, this study explores natural or unrefined sweeteners such as honey, date syrup and jaggery as potential alternatives due to their nutritional and therapeutic properties.

Experimental approach: The study aims to optimize the amounts of honey, jaggery and date syrup to substitute the addition of sucrose for sweetness in guava nectar prepared using two processing treatments: hot filling and cold filling. The bioactive and rheological properties, mineral composition (in-vitro bioavailable iron) and storage stability of the nectar were further evaluated. During storage, the formation of 5-hydroxymethylfurfural (HMF), effects on antioxidant activity and non-enzymatic browning were monitored to assess changes in overall quality.

Results and conclusions: The amount of sucrose substitution in guava nectar was optimized at mass fractions of 50, 25 and 30 % for honey, jaggery and date syrup, respectively, based on organoleptic properties. The optimized formulations showed a significant improvement in total phenolic content and radical scavenging activity. The guava nectar showed pseudo-plastic behaviour with a weak gel structure due to the dispersion of pulp particles, which contributed to its viscoelastic nature at low strain (<10 %). The substitution of sucrose with natural sweetener resulted in increased mineral content; however, the bioavailability of iron considerably decreased. During storage, degradation of ascorbic acid and colour, acceleration of non-enzymatic browning and development of 5-hydroxymethyl furfural were notably high by the end of the sixth month, but the formulations remained microbiologically stable.

Novelty and scientific contribution: New products can be formulated using natural sweeteners instead of sucrose, which may offer higher nutritional and therapeutic value. However, in this study, the product could be improved by further research to reduce negative effects on quality characteristics during storage.

This review provides a comprehensive analysis of bacterial cellulose production, with a focus on the key factors influencing the bioprocess, including microorganism selection, substrate optimization and cultivation techniques. It addresses the challenges associated with bacterial cellulose production and proposes strategies to optimize upstream processes, such as microorganism preservation, inoculum preparation and culture medium formulation, which are critical for improving production efficiency. Additionally, the review explores the effects of fermentation parameters such as time, temperature, and oxygen availability on the yield and quality of bacterial cellulose. It also highlights the growing interest in utilizing alternative substrates, particularly agro-industrial waste, to reduce production costs and improve sustainability. By evaluating these factors, this review provides valuable insights for the further development of bacterial cellulose production in both research and industrial applications.

Research background: Although there are many studies of the bioimprinting of lipases, there is no study comparing the strategies of bioimprinting prior to immobilization (pre-immobilization) and bioimprinting after immobilization (post-immobilization). Likewise, there is no study that compares bioimprinting of lipases immobilized from a pure lipase preparation and lipases immobilized from a crude extract. We therefore investigated these strategies, using the metagenomic lipase LipC12.

Experimental approach: We immobilized LipC12 covalently on the commercial support Immobead 150P and treated it with various bioimprinting agents, either pre-immobilization or post-immobilization. We also compared immobilization from a pure LipC12 preparation and immobilization from a crude cell-free extract.

Results and conclusions: The best improvements in triolein-hydrolyzing activity in n-hexane, compared to a non-bioimprinted control, were obtained with post-immobilization bioimprinting, using oleic acid dissolved in t-butanol: a 12-fold improvement for immobilization from a pure LipC12 preparation and an almost 14-fold improvement for immobilization from the crude cell-free extract. This bioimprinting agent also gave a 3.5-fold increase in activity for the synthesis of ethyl oleate in n-hexane, this result being obtained for pre-immobilization bioimprinting and immobilization from the cell-free extract.

Novelty and scientific contribution: This study is the first to compare pre-immobilization and post-immobilization bioimprinting strategies, as well as bioimprinting of enzymes immobilized from both pure enzyme preparations and crude cell-free extracts. These results encourage further investigation into bioimprinting strategies.

Research background: Anthocyanins, the most abundant pigments in red wine, play an important role in the visual aspect of wine sensory properties. However, due to their unstable nature, their ability to polymerise with tannins is important for colour stability. Their content varies with grapevine variety, growing conditions, viticultural and winemaking practices. Leaf removal, a common viticultural practice, enhances anthocyanin accumulation in red grapevines, and partial fruit zone leaf removal at different phenological stages can significantly influence the anthocyanin content of grapes and wine. This two-year study examined how two different times of fruit zone leaf removal at different phenological stages affect the initial anthocyanin content in wine and their stability during ageing in Merlot, Syrah and Cabernet Sauvignon wines grown in a Mediterranean climate.

Experimental approach: Partial leaf removal was applied during flowering and during vérasion and compared with untreated control. The wines obtained from all treatments and varieties were bottled two months after the end of fermentation, and then stored and matured under the cellar conditions for one year. To determine the influence of different times of leaf removal on the concentration of anthocyanins and their stability in the wine, the wines were analysed immediately after bottling and again after 6 and 12 months of storage. For the determination of all phenolic compounds, high-performance liquid chromatography (HPLC) was used.

Results and conclusions: Leaf removal treatments increased the concentration of anthocyanins in all three cultivars. The obtained results showed that malvidin-3-O-glucoside (Mal-3-Glc) was the most abundant individual anthocyanin, while the most unstable anthocyanin was petunidin-3-O-coumaroyl glucoside (Pet-3-Coum-Glc). Initial concentration of total anthocyanins in all wine samples was significantly affected by different conditions in the two years of study, but with a significant effect of the defoliation treatments. Anthocyanin concentration decreased during the ageing of the wine, and the degradation of anthocyanins ranged from 36 to 90 %. The stability of anthocyanins in wine was most influenced by ageing time, while year and treatment had no influence. The concentration of total phenolic acids increased during wine ageing, while the concentration of total flavonol glycosides (TFG) decreased in all wine samples except Merlot from 2016.

Novelty and scientific contribution: The results of this study contribute to a better understanding of the stability of increased concentrations of anthocyanins in wines during ageing obtained by the practice of grapevine leaf removal in the vineyard.

Research background: Nowadays, there is still no portable electroanalytical device suitable for the monitoring concentration of chlorophenols in technologically used water, especially in the brewing industry. This problem could be solved by developing an electroanalytical screening method based on chlorophenol anodic oxidation.

Experimental approach: The electrochemical behaviour of the target chlorophenols was investigated to find the optimum working conditions for their selective electrochemical detection in beer.

Results and conclusions: Electrochemical oxidation pathways were proposed for each investigated chlorophenol. The sum of all chlorophenols present in the brewing water, expressed as the concentration equivalent of 2,6-dichlorophenol, can be determined electrochemically, so that in future real-time monitoring of chlorophenols in the individual stages of the beer production process will be possible. Moreover, the cathodic reduction of their oxidation products proved to be a suitable electroanalytical tool for the selective detection of their presence in beer.

Novelty and scientific contribution: The research shows that an electroanalytical approach could be useful in the control of beer biotechnology to prevent sensory changes caused by the chlorophenols formed.