Food Technology and Biotechnology最新文献

Research background: Oxidative stress plays a crucial role in different diseases, including chronic hepatitis, cirrhosis and liver cancer, which are a major cause of mortality worldwide. Liver cell injury resulting from oxidative stress contributes to the development of these diseases. Garlic is known for its diverse physiological activities, and black garlic, produced by thermal ageing of raw garlic, has attracted attention due to its biological properties.

Experimental approach: This study investigates the hepatoprotective potential of black garlic prepared in an electric cooker. The study includes mass loss, browning index, free amino acids, free-reducing sugar content, total phenolic compounds and DPPH radical scavenging activity. Additionally, the sensory evaluation shows a preference for the black garlic sample over raw garlic. The study also investigates the activation of Nrf2-ARE pathway in HepG2-C8 cells and evaluates the protective effect against H₂O₂-induced damage.

Results and conclusions: The results indicate that black garlic lost mass, possibly due to water loss and the Maillard reaction, which led to an increase in the browning index and a decrease in free amino acids. However, the content of free reducing sugars increased. After 14 and 21 days, the total phenolic content of black garlic increased and its ability to scavenge DPPH radicals improved. Significant activation of the Nrf2-ARE pathway was observed in HepG2-C8 cells. Sensory evaluation showed a preference for the 14-day aged black garlic. The Nrf2 pathway can be effectively activated in HepG2 cells by a 14-day aged black garlic extract, resulting in protection against H₂O₂-induced damage.

Novelty and scientific contribution: Our research shows the significant effect of thermal ageing on black garlic and highlights its enhanced antioxidant properties. A simple approach has been developed to prepare black garlic that is more effective, healthier and can potentially be used to protect the liver and treat diseases related to oxidative stress.

Research background: Food safety is threatened by the contamination of fresh fruits and vegetables by pathogenic bacteria, among which the particularly widespread ones are coliform bacteria. Due to the continuous increase in the incidence of severe diseases caused by the consumption of fresh (tomato) fruits contaminated with Escherichia coli, antimicrobial postharvest measures are needed. The problem is that many active antimicrobial compounds have a weak and short-lasting effect and/or are not environmentally friendly. Recently, the antibacterial and antifungal activity of environmentally friendly agent phenylboronic acid (PBA), including on two tomato pathogens, has been reported.

Experimental approach: The aim of this study is to determine the antibacterial effect of PBA on E. coli and three enteropathogenic Enterobacterales, and to check its ability to serve as a bacterial decontaminant of fresh tomato fruits.

Results and conclusions: The minimum inhibitory concentration (MIC) of PBA against E. coli, as well as Shigella sonnei, Salmonella enteritidis and Yersinia enterocolitica was 1.0, 1.2, 1.0 and 0.8 mg/mL, respectively. In addition, we have shown that PBA has a bacteriostatic effect on E. coli at lower concentrations and a bactericidal effect at higher (>3.0 mg/mL) concentrations. Importantly, the study found that an E. coli strain resistant to seven commonly used antibiotics, as well as strains producing extended-spectrum beta-lactamases (ESBL), is as sensitive to PBA as the wild-type strain without any resistance, suggesting that the mechanism of action of PBA differs from that of all these antibiotics. Finally, we have shown that washing and incubating contaminated tomato fruits in PBA solution reduces the growth of E. coli washed from fresh tomato fruits in a concentration- (0.5-3.0 mg/mL) and time-dependent manner, while having no adverse effect on the tomato fruits.

Novelty and scientific contribution: This is the first report on the antibacterial effect of PBA on medically important bacteria E. coli, S. enteritidis, S. sonnei and Y. enterocolitica. Moreover, we show that PBA kills multidrug-resistant E. coli, including those producing ESBL, making it a promising agent against such bacteria. Finally, PBA is shown to be an effective decontaminant of E. coli on fresh tomato fruits.

Research background: Despite being a substantial and expanding market segment, there remain challenges concerning the shelf life of plant-based meat alternatives when synthetic preservatives are not used. Consequently, it is necessary to investigate the integration of natural extracts into these products to extend their shelf life.

Experimental approach: The total phenolic content, flavonoid content and antioxidant capacity of the powder of dried mangosteen peel extract was characterised. The fresh soy-based burgers were then formulated for six treatments including control (no antioxidant added), 10 mg butylated hydroxytoluene (BHT, a synthetic antioxidant), 10, 7.5, 5 and 2.5 mg dried extract and their proximate composition, physicochemical characteristics, protein and lipid oxidation, texture profile and sensory parameters during 10 days of storage were evaluated.

Results and conclusions: The addition of the extract reduced the moisture content and cooking loss. In addition, the burgers with the extract (5-10 mg/100 g) had remarkably lower values of peroxides, thiobarbituric acid reactive substances and carbonyls, indicating their higher stability against lipid and protein oxidation. These effects of the extract proved to be better than those of BHT. The burgers containing the extract also had improved texture in terms of springiness, chewiness and cohesiveness, resulting in higher texture scores. All treatments were accepted by consumers, with the average score of approx. 7 to 9 points. Therefore, the extract from mangosteen peels could be used as an excellent natural antioxidant substitution for synthetic ones currently used in food preservation.

Novelty and scientific contribution: The study fulfils a need for the growing plant-based meat alternatives with an extended shelf life of a healthier version by using a natural antioxidant extract from mangosteen peels instead of synthetic butylated hydroxytoluene. In addition, the study provides an assessment of product quality during storage and presents findings that could drive innovation in the use of natural preservatives in the food industry.

Research background: Cascara, the dried husk of coffee cherries, has attracted attention as a potential beverage due to its unique flavour profile and potential health benefits. Traditionally, cascara is prepared using hot brewing methods. However, recent interest in cold brewing methods has led to research on how temperature affects the functional properties of cascara beverages.

Experimental approach: Colour (CIE L*a*b*), total dissolved solids and titratable acidity were determined in cascara beverages prepared at 5, 10, 15 and 20 °C. The concentration of phenols and flavonoids, as well as antioxidant properties were evaluated using spectrophotometric methods. Caffeine, chlorogenic acid and melanoidins were quantified by HPLC. The mineral composition was determined using inductively coupled plasma mass spectrometry (ICP-MS). The results were compared with a hot-brewed cascara beverage.

Results and conclusions: Cold brewing resulted in significantly higher concentrations of total phenolic compounds, expressed as gallic acid equivalents (ranging from 309 to 354 mg/L), total flavonoids, expressed as quercetin equivalents (11.8-13.6 mg/L), and caffeine (123-136 mg/L) than the hot-brewed cascara beverage sample (p<0.05). Temperature had a noticeable effect on most variables, although the effect appeared to be random. In particular, concentrations of caffeine (p<0.01) and copper (p<0.001) were highest in beverages prepared at 20 °C and decreased with decreasing brewing temperature. Multivariate analysis showed that minerals (As, Co, Mn, Sn, Mg and Ca), hue and phenolic concentration contributed to the first principal component, which mainly differentiated the hot-brewed sample. Antioxidant-related variables, total titratable acidity and Se contributed most to the second principal component, which facilitated the separation of samples brewed at 5 °C.

Novelty and scientific contribution: To our knowledge, this is the first study to suggest that temperature affects the functional properties of cascara beverage produced by the cold brewing method. Experimental evidence supports the existence of a direct proportionality between caffeine and copper concentrations and brewing temperature.

Research background: Encapsulating lemuru fish protein hydrolysate is important to maintain its stability. However, optimal conditions for the encapsulation process of lemuru fish protein hydrolysate using statistical methods remain unexplored. This study aims to address this problem by optimizing the encapsulation conditions.

Experimental approach: Maltodextrin and gum Arabic were used as carrier agents, with mass per volume ratio ranging from 10 to 30 %, and spray dryer inlet temperatures between 90 and 100 °C. In this study, we analysed the main interactions of these variables using response surface methodology (RSM).

Results and conclusions: Our results show that mass per volume ratio of maltodextrin of 25 % and inlet temperature of 100 °C are the optimal conditions for the encapsulation of fish protein hydrolysate. The optimal conditions resulted in a high desirability index of 0.864, indicating an effective balance between yield, solubility and hygroscopicity. The actual results also fall well within the confidence interval of the predicted values, confirming the robustness of the model and the reliability of the predicted optimal encapsulation conditions. Encapsulated fish protein hydrolysate was compared with its non-encapsulated counterpart and characterised using Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and particle size analyser (PSA) to validate the results. The encapsulated fish protein hydrolysate showed distinct properties, such as the presence of functional groups from maltodextrin, interconnected particle and more homogeneous and narrower particle size distribution.

Novelty and scientific contribution: The encapsulation of lemuru fish protein hydrolysate using maltodextrin with mass per volume ratio of 25 % and inlet temperature 100 °C was successful in improving the properties of the protein hydrolysate. Further research should explore the functional properties of fish protein hydrolysate.

Research background: Nowadays, there is a growing interest in active packaging with the addition of natural extracts due to safety concerns and consumer preferences. Physalis angulata is a medicinal and edible species of the Solanaceae family and is rich in phenolic compounds. Phenolic compounds, the secondary metabolites, are synthesised and stored in all plant tissues. They can be used as plasticizers or fillers to improve the interfacial interaction between the two biopolymers and prevent the transfer of moisture and gas from the food product and extend the shelf life to some degree.

Experimental approach: The effect of a three-layer (P/G/B) film based on polylactic acid (P), gelatine (G) and polybutylene adipate-co-terephthalate (B) incorporated or not with Physalis leaf extract (PLE) on the quality changes of fish meat powder (sample) stored at 27-30 °C (30 days) was investigated in comparison with control (uncovered), polyethylene (PE), polylactic acid, polybutylene adipate-co-terephthalate and gelatine films. The samples were sealed in a cylindrical bottle covered with the prepared films. The storage properties such as moisture content, pH, peroxide value (PV), thiobarbituric acid reactive substances (TBARS), total volatile basic nitrogen (TVB-N), changes in colour, sensory properties and volatile compounds of samples packed with the developed films were analysed.

Results and conclusions: The moisture content was lower in the sample covered with the P/G/B-PLE-7 % film throughout the storage period. However, the sample covered with PE film had the highest PV (p<0.05). TBARS, TVB-N and volatile compounds decreased in the sample covered with P/G/B-PLE-7 % on day 30 of storage. The incorporation of Physalis leaf extract into the three-layer film improved the properties of the film and extended the shelf life of fish meat powder. Thus, the addition of Physalis leaf extract to the three-layer film could serve as a biodegradable active packaging and be a promising substitute for commercial plastic films.

Novelty and scientific contribution: This is the first report on the study of chemical changes of fish meat powder covered with a three-layer (P/G/B) film incorporated with Physalis leaf extract. This will lead to a better understanding of the role of the three-layer (P/G/B) film containing Physalis leaf extract on the extension of shelf life of fish meat powder.

Research background: In India, widespread dietary deficiency in calcium and vitamin D is a significant public health concern. Over the past five decades, evidence has shown a decline in dietary calcium intake in rural, tribal and urban populations. This persistent deficiency poses a serious risk to bone health and contributes to the development of rickets, osteoporosis and osteopenia, as well as potential disturbances in metabolic rates and physiological functions. A key factor in this decline appears to be the reduced consumption of calcium-rich dairy products. As a result, research is exploring alternative, highly bioavailable sources of calcium, such as those derived from fish bone waste. The potential of nano-calcium supplements to improve absorption and bone density compared to traditional supplements is an area of active investigation.

Experimental approach: Nano-calcium powder was synthesised from the bones of two commercial fish species, Daysciaena albida and Otolithes ruber, ethically sourced from the Kerala coast following relevant regulations. Alkali extraction method was used and the resulting nano-calcium powder was characterized by various physiological and chemical analyses.

Results and conclusions: The yield percentage of two samples was different. Notably, both samples had different colour properties, proximate composition and results of scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX). The nano-calcium from D. albida also contains slightly more calcium and phosphorus than that from O. ruber. The nanoparticles of the calcium from D. albida (d=153.8 nm) were also smaller than the nanoparticles of the calcium from O. ruber (d=337.1 nm). Interestingly, further analyses using techniques such as Fourier transform infrared spectroscopy (FTIR), zeta potential, thermogravimetric analysis (TGA) and X-ray diffraction (XRD) showed significant similarity between the nano-calcium samples from D. albida and O. ruber, despite the initial differences in yield, composition and particle size. This result suggests that the choice of fish species significantly affects the yield, composition and properties of the synthesised nano-calcium powder with D. albida appearing to be a more favorable source, but both products can exhibit similar functionality and warrant further investigation.

Novelty and scientific contribution: This is the first report on the extraction and characterization of biogenic nano-calcium from two commercial fish, Daysciaena albida and Otolithes ruber from the Malabar Coast, India. The extracted nano-calcium powders from these two fish are a good source of calcium and help overcome calcium-related disorders.

Research background: Hydrodistillation is a convenient and economical method to extract essential oils, but this technique has been abandoned due to limited extraction rates. Comparison to conventional hydrodistillation, maceration-mediated hydrodistillation could increase mass transfer and provide better control over the extraction thermodynamics, thereby preserving the aroma constituents and their antioxidant activities. The present study describes a useful and innovative modification of conventional hydrodistillation by introducing a macerating agent Triton X-100 and NaCl as an electrolyte to accelerate mass transfer for better extraction of caryophyllene-rich essential oil from sea buckthorn berries.

Experimental approach: The parameters of maceration-mediated hydrodistillation, including the mass fraction of macerating agent, electrolyte concentration and extraction time, were investigated within a wide range of 1-10 %, 1-10 g/100 mL and 3-8 h, respectively, to increase the oil yield (g/100 g). The parameters were optimized according to the desirability approach using response surface methodology. The antioxidant activity of the essential oil obtained under optimal conditions was measured using in vitro antioxidant assays and its aroma profile using gas chromatography with mass spectrometery (GC-MS).

Results and conclusions: The optimized parameters for the modified hydrodistillation were observed at 4.22 mL Triton X-100 and 4.03 g NaCl for 5.61 h of extraction time with the essential oil yield of (3.2±0.1) % compared to 2.1 % obtained with conventional hydrodistillation. The essential oil produced by the assisted hydrodistillation was rich in (-)-β-caryophyllene (37.2 %) with good antioxidant activities in terms of free radical scavenging capacity (84.2 %), inhibition of linoleic acid peroxidation (68.2 %) and antioxidant capacity expressed in Trolox equivalents (168 µmol/mL).

Novelty and scientific contribution: Triton X-100 can disrupt the cell membrane to release the bioactive compounds, while the NaCl reduces the solubility of the non-polar components of the essential oil in the aqueous phase, which can ultimately improve the extraction yield. The proposed approach can be used with minor modifications with the existing hydrodistillation setups and it seems to be more economical for the extraction of sea buckthorn essential oil without compromising its antioxidant potential or its valuable aroma compounds on an industrial scale.

Research background: Glucomannan is a polysaccharide compound used widely in food and pharmaceutical industries. The tuber of Amorphophallus muelleri Blume is called porang in Indonesia. Ethanol extraction is commonly used to extract glucomannan from porang flour; however, the method has some limitations. Glucomannan obtained by ethanol extraction has a higher protein content than standard glucomannan. In this work, the salting-out effect of the salts of the aqueous two-phase system was investigated for the extraction of glucomannan. In this way, the protein can be removed from the glucomannan flour, thus increasing the purity of the obtained glucomannan.

Experimental approach: A novel glucomannan extraction method using an aqueous two-phase system (ATPS) consisting of salt and ethanol was investigated. The Na₂HPO₄ and K₂HPO₄ salts at 3 different mass fractions (1, 2 and 3 %) mixed with 40 % ethanol in a 1:1 volume ratio were used to prepare the ATPS. The efficiency of ATPS in the extraction of glucomannan was based on the phase separation and better properties of glucomannan, including proximate composition, colour, thermal properties and surface morphology were obtained. Statistical analysis was performed to test the significant differences between the mean values of each treatment. The statistical significance level was set at p=0.05.

Results and conclusions: The results showed that the aqueous two-phase system was able to separate a solution of porang flour into three layers, namely bottom (F1), middle (F2) and top (F3) layer. The bottom (F1) and middle (F2) layers were rich in glucomannan and starch, respectively, while the top layer (F3) consisted of an ethanol-soluble compound. The salts affected the yield of glucomannan and the properties of the obtained glucomannan, including colour, impurities (protein and ash), thermal properties, molecular mass and surface morphology. Increasing salt mass fraction decreased the yield of glucomannan but increased the yield of other components. ATPS reduced the protein content and increased the lightness of the glucomannan. The glucomannan obtained with ATPS had a higher thermal stability than the control.

Novelty and scientific contribution: Salting-out ability of the salt of the aqueous two-phase system is commonly used in protein precipitation and isolation. However, there was no report found on the application of ATPS for the isolation of glucomannan. This study has shown that the ATPS (ethanol/Na₂HPO₄ and ethanol/K₂HPO₄) is a potential new extraction method for glucomannan extraction.