Food Technology and Biotechnology最新文献

Research background: Anthocyanin pigments in mangosteen pericarp can serve as natural colourants; however, their stability is compromised by enzymatic browning caused by polyphenol oxidase (PPO). Thus, this study aims to investigate how hot water and steam blanching affect the PPO activity, phenolic profile and antioxidant properties of mangosteen pericarp.

Experimental approach: Fresh mangosteen pericarp was blanched in hot water or steam at 100 °C for 0, 30, 60, 90 and 120 s and the residual PPO activity, total phenolic content (TPC), total anthocyanins, antioxidant activity, browning index and colour properties were evaluated. Additionally, the phenolic compounds were identified using liquid chromatography-mass spectrometry (LC-MS).

Results and conclusions: Zero-order reaction kinetics (R²>0.800) showed that residual PPO activity was significantly (p<0.05) reduced in both blanched and steamed mangosteen pericarp. As expected, PPO was inactivated more rapidly in hot water (t _1/2=59.0 s) than in steam blanching (t _1/2=121.1 s). However, the principal component analysis (PCA) showed that steam blanching for 90 s was the most efficient method, preserving the highest levels of antioxidant capacity, expressed as Trolox equivalents (TE; 9135 µmol/g), Fe(III)-reducing power, expressed as TE, (9729 µmol/g), total anthocyanins (3.03 mg/g), and TPC, expressed as gallic acid equivalents (1057 mg/g). Overall, steam blanching for 90 s was the most efficient method because it best preserved the phenolic compounds and is also a cost-effective method compared to hot water, which needs to be replaced after a few applications.

Novelty and scientific contribution: This is the first study to report the effects of blanching on the anthocyanins mainly present in mangosteen pericarp, in particular cyanidin-3-O-sophoroside (C3S) and cyanidin-3-O-glucoside (C3G), using high-performance liquid chromatography (HPLC) and LC-MS. This study makes a significant scientific contribution to the food industry by providing suitable blanching methods to preserve the quality of bioactive compounds, especially anthocyanins in mangosteen pericarp, which can be used as a natural colourant.

Over the last decades, eating habits have shifted towards convenient foods with shorter preparation times due to people's busy lifestyles and higher living standards. Rapid changes in dietary patterns and lifestyles with the industrialization and globalisation have led to the escalating incidence of chronic diseases, which has paved the way to greater interest in dietary changes regarding nutritional status and health benefits. Composite flour is a combination of wheat and non-wheat flours or exclusively non-wheat flour with improved nutritional value, therapeutic properties and functional characteristics. The application of composite flours in the food industry is an important milestone that maximises the use of indigenous crops while optimising the product quality, nutritional value, organoleptic properties and consumer acceptance. This paper provides a comprehensive overview of the suitability and compatibility of alternative composite flours in the food industry with regard to the existing formulations. Furthermore, the suitability of composite flours in food products in terms of nutritive and therapeutic value is emphasised. It was found that food products with higher nutritional and therapeutic value and acceptable sensory properties can be formulated by blending different non-wheat flour sources with wheat flour at different ratios. Composite flours have the potential to reduce the risk of non-communicable diseases, particularly type 2 diabetes, cardiovascular disease and cancer. It can be concluded that the use of composite flours in the food industry is a trending approach due to their numerous benefits.

Research background: Recently, consumers have been increasingly interested in highly nutritional and health-promoting products in the form of functional foods that are produced using environmentally friendly processes as part of the circular economy. Therefore, much research has been carried out related to the valorisation of waste generated during the processing of food, especially fruit and vegetables, commonly referred to as by-products. These by-products consist of peels, seeds, stems or pomace, which have been shown to have valuable nutritional properties (high content of polyphenols, vitamins, antioxidants, etc.).

Experimental approach: Considering these aspects, the aim of this study is to characterise three types of by-products of apple processing, namely peel, pulp pomace and whole fruit pomace, from a nutritional point of view. The total content of polyphenols, antioxidant activity, ascorbic acid (vitamin C) and phenolic content were determined in nine apple varieties from two harvest years (2020 and 2021) during 9 months of storage.

Results and conclusions: The results showed that apple peel had good nutritional properties, in contrast to the pulp or the whole fruit, which are often removed during apple processing. Therefore, the analysed by-products are suitable candidates for application in the food industry for the development of new products enriched with bioactive compounds.

Novelty and scientific contribution: In this study, nine varieties of organic apples were analysed and the nutritional parameters were determined. The phenolic compounds of the studied apple by-products were analysed for possible reuse of apple processing waste.

Research background: Given the potential of microbial exopolysaccharides from lactic acid bacteria in various industrial processes, alternative sources for the isolation of lactic acid bacteria are highly topical. In this study, we used a traditional sourdough from einkorn (Triticum monococcum L. ssp. monococcum) as a source of lactic acid bacteria for the isolation, identification and determination of exopolysaccharide producers.

Experimental approach: The sourdough was prepared from einkorn according to the traditional method. Lactic acid bacteria were isolated and purified using the single colony technique on MRS and M17 media. The isolates were characterised using matrix-assisted laser desorption ionization-time of flight mass (MALDI-TOF) spectrometry. All isolates were analysed for extracellular polysaccharide production and one isolate was selected for purification and characterisation of its polysaccharide.

Results and conclusions: The isolates were identified as Lactobacillus plantarum, L. paraplantarum, L. brevis, Pediococcus pentosaceus, Enterococcus faecium and E. durans. The production of exopolysaccharides by all lactic acid bacteria was evaluated and it was found that all strains (except one) were capable of producing exopolysaccharides. One polysaccharide (EPS-SL70) was purified from the isolates of E. durans SL70. This anionic heteropolysaccharide had, in addition to the carbohydrate backbone, a protein structure that did not contain nucleic acid. The carbohydrate backbone consisted of mannose, glucose, rhamnose, arabinose, xylose and galactose.

Novelty and scientific contribution: The microbial flora of traditional einkorn sourdough has been identified in this study and represents the first report on the exopolysaccharide production by lactic acid bacteria in traditional einkorn sourdough. Additionally, Enterococcus durans from einkorn sourdough was identified as a new exopolysaccharide producer.

Plant-based beverages are water-soluble extracts of cereals, pseudocereals, seeds and legumes that resemble milk in appearance. However, these products have important differences compared to normal liquid milk, such as nutritional composition, sensorial properties and shelf-life stability. Increasing number of consumers are opting for these beverages due to lactose intolerance, milk protein allergies or lifestyle. In this regard, different emerging technologies have been investigated to solve problems such as shelf life, nutritional and emulsion stability as well as sensory acceptability, without using high temperatures since heat treatments decrease the content of some bioactive compounds. Ultrasound technology alone or combined with temperature (thermosonication) could be a valuable tool to improve the properties of plant-based beverages. Therefore, this review provides a detailed analysis of the effect of ultrasound and thermosonication on the physical, bioactive, microbiological and sensory properties of almond-, soybean-, coconut-, hazelnut- and peanut-based beverages, among others.

Research background: In recent years, there has been a growing interest in incorporating fruit-based additives into yogurt formulations as a means to improve the functionality of the product. This study aims to produce a functional product by incorporating quince, which is rich in fibre, vitamins, minerals and antioxidant activity, into a yoghurt formulation.

Experimental approach: The influence of the addition of quince powder (0 (control), 0.5, 1.0 and 1.5 %) on the antioxidant and proteolytic activities and culture viability of probiotic yoghurt was investigated for 28 days.

Results and conclusions: The viable counts of yoghurt bacteria and Bifidobacterium lactis BB-12® were above 8 log CFU/g. Higher viability of all bacteria was obtained in yoghurt fortified with 1.5 % quince powder than those of other samples after 14 days. Probiotic yoghurt with added 1.5 % quince powder had the highest proteolytic activity during the last two weeks of storage, while the highest total phenolic content and (2,2-diphenyl-1-picrylhydrazyl) radical (DPPH˙) scavenging activity were obtained for the same sample throughout the storage period.

Novelty and scientific contribution: Quince powder supports the health of the digestive system thanks to its high fibre content, while it is also rich in vitamins, minerals and antioxidant activity. These properties emphasise the importance of using quince powder in yoghurt production. This innovation has the potential to provide consumers with a tasty alternative, while at the same time increasing the intake of health-promoting ingredients. Furthermore, such products offer higher nutritional value than conventional yoghurt, offering consumers with a healthier option. Therefore, the production of yoghurt with quince powder can be considered as an important innovation in the field of nutrition and a practice that contributes to increasing health awareness.

Research background: With the increasing consumption of food commodities, particularly rice, and the substantial volume of food imports in Indonesia, there is an increasing need to explore alternative food sources. Rice analogues emerge as a potential substitute for traditional rice, serving as a viable staple food option. The aim of this study is to investigate the effect of the composition of raw material, namely sago and corn flour, on the physicochemical properties and consumer acceptance of rice analogues.

Experimental approach: The rice analogues were produced using the hot extrusion method. The nutritional content (protein, carbohydrate, fat, moisture, fibre and ash) of the product was then analysed. Thermal stability and morphological properties were determined using differential scanning calorimetry (DSC) and scanning electron microscopy (SEM), respectively. A consumer acceptance test including taste, texture, aroma and colour was also carried out to evaluate the quality of cooked rice analogues.

Results and conclusion: The results showed that the rice analogue produced by hot extrusion at 70 °C with black-eyed beans (15 % m/m) and skimmed milk powder (0.5 % m/m) had the most significant nutritional improvements such as increased content of protein, fat, carbohydrate, moisture content, ash and fibre. However, it should be noted that increasing the extrusion temperature above 70 °C meant that both density and hardness could no longer be controlled due to gelatinisation. Furthermore, 30 participants in the consumer acceptance test rated the texture, aroma, taste and colour positively, underlining the potential of rice analogue as a nutritious and attractive alternative to natural rice. The rice analogue made from modified sago with additional ingredients of corn and black-eyed beans has similar properties to natural rice.

Novelty and scientific contribution: The combination of sago, corn and black-eyed bean flour as the main ingredients of the rice analogue is a novelty of this study. Furthermore, its nutritional profile exceeds that of natural rice, making it a viable and acceptable alternative in times of rice scarcity.

3-Monochloropropane-1,2-diol (3-MCPD) and its esters, which have carcinogenic and genotoxic effects, are contaminants induced by high-temperature that have been detected in refined oils and fatty foods. 3-MCPD esters, chlorinated propanols, were first identified in 1978 in acid-hydrolysed vegetable proteins used as flavour enhancers in many foods. Glycidyl esters (GE) are contaminants that can occur in edible oils during heat treatment and are formed mainly during the deodorisation phase of refining. The International Agency for Research on Cancer has classified 3-MCPD as a 'potential carcinogen for humans' in group 2B. Glycidol has also been classified as group 2A with mutagenic and carcinogenic properties, i.e. 'probably carcinogenic to humans'. In addition, glycidol has been classified by the International Agency for Research on Cancer (IARC) as a 'possible human carcinogen' (group 2A). Toxicological studies have shown that these genotoxic and carcinogenic contaminants induced by heat treatment are released in the gastrointestinal tract and cause the formation of tumours. In this review the mechanisms of formation, toxicological effects of 3-MCPD and GE on human health, and methods of their detection are shown. The latest strategies to mitigate and prevent 3-MCPD and GE formation during crude oil production, refining and beyond are also discussed.

Research background: Virgin olive oil, known as a good source of health-promoting hydrophilic phenols, is traditionally used as a medium for preserving various foods. Phenols in general can form complexes with proteins, but there is little information on the direct contact of virgin olive oil with protein-rich food during long-term storage. In this study, the dynamics of the decline of total phenols in oil used as preservation medium for a traditional (whey cheese skuta) and a modern product (tofu) were compared.

Experimental approach: Pieces of skuta or tofu immersed in virgin olive oil at different food-to-oil mass ratios were stored in the refrigerator for up to 21 days. The oil quality indices, water content and the total count of aerobic mesophilic bacteria in the immersed materials were monitored. To determine the total phenols in the oil, the optimal conditions of the Fast Blue BB test, which is a suitable alternative to the standard method, were tested and selected.

Results and conclusions: The effect of both materials on the indicators of hydrolytic and oxidative deterioration of the oil is almost identical (a gradual decrease), which is most likely due to the continuous release of water from the immersed food. A sharp decrease in total phenols in the oil (by about 50 %) after seven days of storage in contact with both materials indicates a combination of causes (water-to-oil migration and phenol-protein interactions). The form of the rational function is highly representative of the decrease in total phenols during the first seven days of tofu/oil storage, indicating a very rapid interaction with tofu proteins. The preservative effect of virgin olive oil in terms of microbiological spoilage was not observed.

Novelty and scientific contribution: The results of this study contribute to the knowledge on the dynamics of phenol-protein interactions and emphasise the need for further investigations on traditional or newly used protein-rich foods preserved in direct contact with virgin olive oil, taking into account possible changes in the functional, nutritional and sensory properties of phenols and proteins.

Research background: Authentic Mexican cheeses have potential health benefits, although there are few studies on their bioactive components. In this study, we analysed soluble extracts from añejo cheese from Zacazonapan (Mexico), obtained from two dairies (A and B) that used milk from cows of different breeds and differed in processing.

Experimental approach: The soluble extracts of Zacazonapan añejo cheese during ripening (0, 30, 95 and 180 days) were used to determine proximate composition, amino acid composition, peptide profile, molecular mass profile, antioxidant and antihypertensive activities.

Results and conclusions: The molecular mass of the released protein fragments ranged from 0.10 to 22.43 kDa. During ripening, amino acids such as Pro, His, Tyr, Trp, Met, Cys, Ala, Gly, Leu and Val were present, which are associated with antioxidant activity. The inhibition of β-carotene bleaching was below 50 % at all ripening times. A significant difference between the cheese samples was observed only after 180 days. Amino acids associated with angiotensin-I converting enzyme (ACE-I) inhibition were found in the extracts (Trp, Phe, Tyr, Pro, Lys and Arg). The highest activity was observed in cheese ripened for 180 days (IC₅₀ of cheese A and B was 0.38 and 0.42 mg/mL, respectively).

Novelty and scientific contribution: These results suggest that Zacazonapan añejo cheese is a potential source of antioxidant and antihypertensive peptides, which are influenced by the dairy factor (milk source and production technique) and ripening time. This is relevant as there are no reports of these bioactivities in this type of cheese.