Journal of Food Science and Technology最新文献

Chocolate is often used in 3D food printing, however in 3D food printing cold extrusion systems, chocolate often faces the issue of temperature-induced clumping. To address this texture alteration, the method of adding oleogels is employed. This study examines the impact of monoglycerides (MAG), sucrose fatty acid ester (SE) and hydroxypropyl methylcellulose (HPMC) oleogels on the thermal and textural properties of 3D printed white and dark chocolates. It compares the effects of adding MAG, SE, and HPMC to dark and white chocolate for 3D printing. Thermal analysis shows distinct melting points: white chocolate with MAG peaks at 29.53 °C, 32.46 °C and 37.08 °C, while dark chocolate with SE peaks at 29.79 °C and 31.78 °C. Texture analysis indicates that white chocolate with 2% SE is harder than with 2% MAG, correlating with their respective melting points. AI image recognition effectively identifies shape variations and defects, achieving recognition rates over 90% for ideal shapes and flagging incomplete extrusions and structural issues. These findings highlight 3D printing's potential in chocolate manufacturing for precise customization and quality control, supported by AI inspection systems. Besides, the method offers a simpler approach for future applications for non-thermal extrusion. Future research could optimize oleogel formulations and expand AI applications to enhance production efficiency and product consistency.

Dairy products such as yogurt are nutritious food sources. Propolis is formed by mixing tree secretions with pollen and bee enzymes and has some functional properties. Basil seed is a rich source of hydrocolloids with outstanding functional properties. It gum has excellent potential for use as a fat substitute in yogurt. Pasteurized milk containing 2% w/v starter was investigated with different propolis extract and basil seed mixtures. Then, on days 1, 3, 6, 14, and 21, the yogurt samples’ physiological, rheological, sensory, and antioxidant properties were investigated. Propolis significantly increased (p < 0.05) the antioxidant activity, phenolic compounds, and color index; nonetheless, it reduced sensory acceptability. The basil seed gum significantly increased (p < 0.05) textural and rheological characteristics, acidity, brightness, and sensory acceptability. The sample containing propolis and basil gum exhibited the highest water-holding capacity, the highest level of antioxidant activity and phenolic compounds, and the lowest acidity.

Traditional methods for fruit juice preservation use high temperatures, which degrade beneficial compounds like vitamins and antioxidants. Membrane filtration provides a gentler alternative, preserving nutrients through mild operating temperatures. This study assessed the temperature and pressure influence on watermelon juice microfiltration, focusing on permeated flow, lycopene, sugars, phenolic compounds, and flavonoids. Using a 2² composite design with central values, optimal conditions were determined by the desirability function, with pressure at 1.0 bar and temperature at 37ºC, maximizing these response variables. Resistance to permeated flux was primarily due to fouling, with an initial 25% flux reduction. The process effectively concentrated lycopene, sugars, phenolic compounds, and flavonoids, although mineral content decreased in both concentrated and permeated juice, with potassium being the most abundant mineral. The concentrated juice showed greater mineral loss than pasteurized due to retention during microfiltration. Under optimized conditions, microbial load reduction allowed the concentrated juice a shelf life comparable to pasteurized juice (14 days). Sensory analysis showed strong consumer acceptance, with 64% of tasters expressing purchase intent. These results suggest commercial viability for the concentrated juice; moreover, its high carotenoid retention could serve as an industrial ingredient for functional foods.

To understand their importance, we performed a comparative study on fixed, total, and essential oils from the seed and aril of Myristica fragrans. The total, essential, and fixed oils content of nutmeg (34.47%, 5.95%, and 26.43%, respectively) and mace (22.55%, 8.79%, and 23.73%, respectively) showed varied oil content. The major fatty acid in mace fixed oil (MFO) and mace total oil (MTO) was palmitic acid (33.30% and 33.11%. respectively), whereas, in nutmeg fixed oil (NFO) and nutmeg total oil (NTO), it was myristic acid (62.52% and 58.20%, respectively). MTO exhibited the highest total phenolic (~ 4596 mg gallic acid equivalent/100 g) content. The phenolics and the flavonoids (mg/100 g), such as catechin (25.40 ± 16.11) and quercetin (13.86 ± 2.34), were high in MFO. Rutin (20.61 ± 3.91) and gallic acid (10.69 ± 1.58) were highest in MTO. Ferulic acid (8.26 ± 0.49) was highest in NTO, and synergic acid (24.72 ± 3.41) in NFO. The MFO showed the highest antioxidant activity (53% radical scavenging activity by DPPH; 34 M Trolox equivalent/ 100 g of oil by TEAC assay; 104 M Trolox equivalent/ 100 g of oil by FRAP assay), correlating with the polyphenols content. The fixed oils showed higher overall antioxidant activity than essential oils.

To minimize the liquid splashing in vacuum cooling, the mass and temperature changes of liquid food were measured by changing the conditions such as the volume ratio of the solution to the container, the pore area, the initial temperature and the terminal temperature, and the effects of different conditions on the ineffective water loss rate were derived from the test results. When the opening area is 1.13cm², the ineffective water loss rate is the largest. The higher the initial temperature, the smaller the ineffective water loss rate. The terminal temperature is 25 °C, the ineffective water loss rate is the lowest. By exploring the key factors of the splash of liquid droplets in the process of vacuum cooling liquid food, the effect of reducing the splash of liquid droplets in the process of vacuum cooling is realized.

Graphical Abstract

The use of whey as an alternative culture medium for fermentation by lactic bacteria enables generating new products exopolysaccharide (EPS) and avoids environmental and economic damage. This work aimed to characterize the exopolysaccharide obtained from whey fermentation (EPS-LN60) by Lactiplantibacillus plantarum DF60Mi to identify its physical and chemical properties. The EPS was characterized in terms of total sugar, protein, yield, FTIR, thermogravimetry, calorimetry, monosaccharide composition, optical microscopy and SEM. High EPS yield (777 mg/L) and sugar content (43.78%) were obtained, as well as, as expected, low protein content (1.82%). The monosaccharides found in EPS-LN60 were galactose (51.1%), mannose (22.9%), glucose (20.8%) and rhamnose (5.2%). The EPS-LN60 spectrogram showed the same bonds and functional groups to the identity of polysaccharides and the thermogram showed high thermal stability (310 °C). The EPS showed a porous surface and leaf shape, indicating its potential application for rheological changes in foods. Therefore, the results confirmed the presence of a heteropolysaccharide with high thermal stability from whey fermentation whose use can be envisioned as a potential ingredient to be explored by the food industry.

Graphical abstract

Milk and dairy products are the most common and widely consumed foods. At the same time, milk is often contaminated with pathogenic microorganisms by endo- and exogenous ways, which can cause various defects in raw materials and finished products. Recently, new techniques have been developed for monitoring microbiological indicators of milk, which are characterized by simplicity, ease of use and high reliability. In addition, the analysis time using the new techniques is significantly reduced compared to traditional ones. The review considers the microflora of milk and ways of its contamination with pathogenic microorganisms, as well as new methods for monitoring microbiological indicators that will be useful for specialists in the dairy industry.

Pyrodextrins are polysaccharides with the potential to be used as food additives, standing out for their nutritional interest associated with their behaviour as soluble dietary fiber. Being isolated from a gluten-free cereal, it is possible to add them to products suitable for individuals with coeliac disease. In the present study, the impact of the spray drying process of sorghum pyrodextrins obtained by pyroconversion of beer mashing residues, is investigated. The operating conditions for laboratory-scale drying are optimised to produce a stable powdered material for storage. The response surface methodology was used for different drying air inlet temperatures (150–250 °C), feed flow rates (20–80%) and drying airflow rates (20–80%). To characterise the spray-dried sorghum pyrodextrins, their water activity, moisture content, colour, particle size distribution and glass transition temperature were analysed. It was verified that the operational variables evaluated had an impact on the characteristic parameters of sorghum pyrodextrin powders. The optimal drying conditions determined a drying air temperature of 181.9 °C, feed flow rate at 23% and drying airflow rate at 78%, allowing powders with stability suitable for conservation to be obtained. The utilisation of a substantial waste from another process enhances efficiency and contributes to sustainability.

The wild yeast Saccharomyces eubayanus (parental of the lager brewing hybrid yeast) has been intensively studied for brewing applications since its discovery in Patagonia (Argentina), and then in other parts of the world. In this work, cultures of this non-conventional yeast in different physiological conditions were tested in terms of viability and vitality, to understand its behavior and provide tools for biomass quality assessment for brewing. Four dyes were analyzed, and alkaline methylene violet turned out to be the most accurate for S. eubayanus viability measurements. Regarding vitality, cultures in exponential and stationary phases presented shorter lag phase and greater acidification power, indicating a better metabolic state; contrary to what was observed in cultures under starvation and refrigerated for 30 days (stressed); however, these presented the highest subsequent fermentation rate. In addition, culture medium for propagation was optimized from malt extract. Plackett–Burman design allowed identifying the most influential factors for biomass production: yeast extract and acid casein peptone, which were optimized by applying a CCD-RSM. Finally, scaling-up (20 L) allowed the obtention of S. eubayanus starter cultures with an adequate biomass quantity and quality for being transferred to the brewing industry.

Seaweed extract has been applied in many crops to improve plant growth, mitigate plant stress, and enhance fruit quality. Ascophyllum nodosum is a macroalgae that is source of phytohormones, minerals, polysaccharides and antioxidant compounds. These elements can enhance food nutritional value, contributing to human health. The objective was to analyze the potential of Ascophyllum nodosum extract (ANE) applications in tomato, to improve physicochemical and bioactive compounds during storage. Tomato plants were cultivated divided into three treatments, foliar and soil applications of ANE (0.2%), and control. Intermediate fruits were harvested and stored for 16 days at 10 ± 1 °C and 90 ± 5% RH to evaluate some postharvest parameters. At harvest, ANE applications increased bioactive compounds, including total polyphenols content (TPC), lycopene, vitamin C and antioxidant activity (AA), as well as chemical parameters like soluble solids and pH. During storage, color parameters, β-carotene, total acidity and firmness tended to decrease as storage time increased. However, TPC, lycopene, vitamin C, AA and weight loss increased during storage. Tomatoes were positively affected by ANE applications on almost every day of storage evaluated, improving their postharvest physiology. Therefore, ANE can be used to extend tomato shelf life and is a great source of beneficial compounds, which are responsible for increasing tomato quality.