Processing of high-protein yoghurt – A review

High-protein yoghurt has gained increased consumer interest over the recent years, partly driven by improvements in taste and texture; there is also greater scientific evidence on dairy protein health benefits. The protein content of yoghurt can be increased prior to fermentation by addition of dairy powder, evaporation or membrane filtration, or after fermentation by straining, mechanical separation, or membrane filtration. Concentration of yoghurt after fermentation produces large volumes of acid whey, a major concern for the dairy industry; by concentrating prior to fermentation, production of acid whey is avoided. Different processing techniques influence yoghurt composition, structure, rheology, and sensory properties. This review discusses the challenges, opportunities, the influence of macro components in milk and different processing techniques on composition, structure, rheology, and sensory properties of high-protein yoghurt, along with their benefits and drawbacks for the dairy producer.     

Equivalence tests – A review

Equivalence tests are becoming increasingly popular in many application areas including sensory sciences. They should be applied whenever the aim of the study is not to show differences, but to conclude similarity.There has been quite some debate about pros and cons of different approaches, reaching the sensory and sensometrics community in recent years. Parts of the sometimes heated debate are, in our opinion, due to mutual misunderstandings, and to different objectives and hence selection criteria for an “optimal” test, boiling down to the question whether power is the only optimality criterion to apply, or whether somehow vague criteria like intuition should be taken into account as well.This review intends to give an introduction into equivalence tests, starting with some general considerations on the statistical testing of hypotheses. We will subsequently give an overview over the most common approaches, some of which are shown to be inappropriate (e.g. the power approach). Some valid and relatively simple methods will be introduced and their correspondence to confidence intervals clarified, while we will skip the mathematical details of some more recent tests. Instead, the pros and cons of different approaches will be discussed and recommendations given.     

Bacillus thermoamylovorans – A new threat to the dairy industry – A review

Bacillus thermoamylovorans is a newly described spore forming bacterium emerging in the dairy industry. There is an increasing threat of B. thermoamylovorans contamination, not only in food ingredients and raw milk, but also in sterilised milk and dairy products. Animal feed, processing equipment, and farm environments are potential entry points for contamination of milk with B. thermoamylovorans. The ability of B. thermoamylovorans to produce lipolytic and β-galactosidase enzymes is linked to food spoilage. B. thermoamylovorans spores have a heat resistance comparable with that of the spores of Bacillus sporothermodurans, indicating the potential to survive ultra-high temperature treatments. However, despite the rise in reports of the isolation of B. thermoamylovorans from dairy samples, there have been few reports on the characterisation of these bacteria. The origin, characteristics and potential issues resulting from B. thermoamylovorans in the dairy industry and potential methods of control are discussed in this review.     

The use of exergetic indicators in the food industry – A review

Assessment of sustainability will become more relevant for the food industry in the years to come. Analysis based on exergy, including the use of exergetic indicators and Grassmann diagrams, is a useful tool for the quantitative and qualitative assessment of the efficiency of industrial food chains. In this paper, we review the methodology of exergy analysis and the exergetic indicators that are most appropriate for use in the food industry. The challenges of applying exergy analysis in industrial food chains and the specific features of food processes are also discussed.     

Technological benefits of inulin-type fructans application in gluten-free products – A review

BackgroundAlthough cereals are used extensively in food products, ingestion of gluten-containing food has been associated with gluten-related disorders in susceptible individuals. Recently, the gluten-free (GF) products are one of the most dynamically growing branches of the food industry. However, many commercially available GF products provide lower level of proteins, dietary fibre, vitamins and minerals, compared with wheat products. To meet the growing demands of GF food consumers, efforts have been made to improve the overall quality of these products. Recently, inulin-type fructans (ITFs) were proposed as the beneficial ingredients of GF products.Scope and approachOver the last decade, the application of ITFs in GF products has been widely explored. Therefore, the aim of this review is to present the current application of ITFs as components of GF products by summarising the existing data concerning their effect on the technological properties and sensory quality of these products in the light of their physicochemical characteristics.Key findings and conclusionsITFs added to the GF products interact with other ingredients and additives. Generally, they have the potential to improve the technological properties and sensory perception of obtained products. The presented facts may provide an inspiration for further intensive work on the improvement of the quality of GF products for the growing number of people struggling with the problem of gluten intolerance.     

Food drying enhancement by ultrasound – A review

BackgroundDrying is one of the most popular methods of preserving a wide variety of food and agricultural products. Unfortunately, this unit operation may negatively influence product quality. Moreover, due to the high heat capacity of water, drying is usually a long-lasting and energy-intensive process, thus new drying techniques are continuously being sought.Scope and approachThis review presents the current state of art in ultrasonic-assisted drying. Despite immense knowledge on the principles of ultrasound generation and action, this technology has found no practical application in industrial drying yet. In this paper we tried to find the reasons for this state of affairs. Up-to-date designs of dryers using ultrasound to enhance the drying process and the various possible mechanisms of accelerating the drying process with the application of ultrasonic waves are discussed. The influence of ultrasound on the product's quality (dried food) is judged and described.Key findings and conclusionsThe analysis of the results presented by the researchers here allows to state that applying ultrasound to drying caused a shortening of the drying time and could reduce total energy consumption. Moreover, due to the small “temperature effect”, the quality of the obtained products was noticeably better as compared to the control processes (without ultrasound enhancement). The lack of an effective technology for generating power ultrasound in air was distinguished as the primary constraint for industrial application of this technology. The necessity of conducting detailed studies on ultrasound application in drying was emphasized.     

Ochratoxin A in liquorice products – a review

Liquorice is a herbal medicine produced mainly in China and Iran. This plant is suspected to contain ochratoxin A (OTA), a secondary metabolite produced by fungi. Although liquorice is not included in the daily dietary of humans, the high levels of OTA reported in this product have concerned consumers. Registration of a standard method for measuring the amount of this mycotoxin in liquorice-derived products is an important challenge and requires the introduction of a reliable, simple, fast-performance and reproducible technique. This review examines studies carried out concerning the occurrence of OTA in liquorice products. Recent information regarding contaminated liquorice, the regulatory framework and methods to degrade OTA in liquorice are discussed.     

Browning development in bakery products – A review

This paper presents a review regarding several aspects of the development of browning during baking of bakery products, mainly from an engineering point of view. During baking, the formation of colour is due to the Maillard reaction, and caramelization of sugars. Besides the major influence of this phenomenon on the initial acceptance of products by consumers, it is the responsible for other relevant changes occurring in food during baking, i.e. production of flavour and aroma compounds, formation of toxic products (e.g. acrylamide), and decrease of nutritional value of proteins. As well as baking, the development of browning in bakery products is a simultaneous heat and mass transfer process that occurs mostly in a non-ideal system under non-ideal conditions. In addition, the mechanisms of chemical reactions involved are still not elucidated completely, so the process is difficult to control and represents a major challenge for food engineers. Effects of browning on properties of products and experimental, modelling and technological aspects of colour formation during baking are reviewed.     

Hot towels: The bedrock of Meibomian gland dysfunction treatment – A review

BackgroundMeibomian gland dysfunction (MGD) reduces quality-of-life and hinders work productivity of millions of patients, with high direct and indirect societal costs. Thickened meibum obstructs the glands and disrupts ocular surface health. Heating the eyelids to soften and express meibum from the glands can be beneficial. The most accessible method for eyelid warming uses heated, wet towels. However, the efficacy of this treatment is reliant on the methodology, and evidence-based best-practice recommendations are needed.PurposeTo evaluate the literature on hot towels in MGD treatment and recommend a best-practice protocol for future research and patient treatment.MethodsStudies were identified through PubMed on the May 28, 2021, with the search terms: (warm* OR heat* OR thermal* OR towel OR wet towel) AND (meibomian OR MGD OR eyelid OR “dry eye” OR DED). All relevant original articles with English full-text were included.ResultsThe search yielded 903 results, of which 22 met the inclusion criteria. Across studies, hot towels were found to be effective at reducing ocular symptoms. However, without reheating, the temperature quickly fell below the therapeutic range, which was deemed to be between 40 °C and 47 °C. Towels heated to around 45 °C and reheated every-two minutes were most effective at increasing eyelid temperature, comparable or better than several commercially available eyelid warming devices. No adverse effects were reported in the studies.ConclusionHot towel treatment effectively warms the eyelids and reduces ocular symptoms, but must be standardized, and towels reheated to achieve maximum benefit. Future research should assess patient satisfaction with different hot towel treatment methods that reheat or replace the towel at least every-two minutes, to establish which methods yield the greatest compliance. Guidelines or clinical recommendations that do not mention the need for regular reheating during hot towel compress treatment should be updated to include this.     

Omega-3 fatty acids – A review of existing and innovative delivery methods

Omega-3 fatty acids are generally under-consumed in Western diets; a factor that may largely be attributed to low intake of oily fish. Although supplementation strategies offer one approach in terms of improving blood fatty acid levels, rates of compliance are generally low due to difficulties in swallowing capsules, or unfavorable aftertastes. Consequently, new approaches, including food-based strategies, may be an alternative approach to improving omega-3 status and the health of public sectors. This paper sets out to discuss and review how the use of novel food vehicle and delivery advancements may be used to improve omega-3 status, which may have wider benefits for public health and well-being.     

Electrically-induced transport phenomena in EHD drying – A review

BackgroundElectrohydrodynamic (EHD) drying is non-thermal and energy efficient technology, which appears to be a viable alternative to thermal drying. However, transport phenomena in EHD are not well understood, which limits practical applications of EHD for drying of biomaterials.Scope and approachThis paper provides a comprehensive review of the fundamentals of electrically-induced physical processes relevant to the theory of EHD drying with particular emphasis on yet existing gaps in the knowledge.Key findings and conclusionsEssential phenomena pertinent to high-voltage electric field and electric wind were examined in terms of heat and mass transfer at the gas-solid interface. The gaps in the knowledge caused by simplifying assumptions in theoretical and experimental studies, as well as omitting some crucial electrically-induced transport phenomena were identified. These include: (i) quantifying energy balance in EHD drying, (ii) uncovering electrically-induced mechanisms of mass transfer in solid, gas and gas-solid boundary layer; (iii) identifying interactions and possibly synergetic effects between electric charge and heat/mass transfer processes; (iv) determining whether average electric wind velocity adequately represents spatial distribution of wind velocity in non-uniform electric field, (v) explaining of some experimental findings, such as temperature drop at the liquid-gas interface, distortion of the free water surface and tangential component of electric wind at the material plane.     

Food choice in low income populations – A review

The vast majority of publications on food acceptability and behavior have considered middle- or high-income populations. However, there is research focused on low-income populations which deserves attention considering that many millions worldwide suffer undernutrition and/or food insecurity. The objective of this review is to highlight what the authors considered to be the most relevant research in the area to thus bring attention to this sensitive area which requires further research. Although there is a certain overlap, the review is classified in the following areas: fruits and vegetables, obesity, food choice, indigenous populations, development of specific food products and, finally, what we consider to be the most promising or necessary research in the field of food choice in low-income populations.     

Functional food ingredients for the management of obesity and associated co-morbidities – A review

Worldwide obesity has reached a pandemic proportion. World Health Organization (WHO) estimates that by 2020, two thirds of the global disease burden will be attributable to obesity and obesity associated complications. Existing anti-obesity drugs, affecting one of the fundamental processes of the weight regulation in human body, have displayed serious side effects which outweigh their beneficial effects. Clinical and non-clinical researchers in this area are now facing a challenge to search for non-pharmacological alternatives for the prevention of obesity. Dietary interventions and life style changes with enhanced physical activity are two such options. Considering the importance of dietary interventions, the present review highlights the role, significance and potential of functional food ingredients for the management of obesity and associated co-morbidities.     

Dromedary camel milk proteins,a source of peptides having biological activities – A review

Many useful properties are assigned to camel (Camelus dromedarius) milk, which is traditionally used for the treatment of tuberculosis, gastroenteritis, and allergy in many countries. Some amino acid sequences, which are encrypted in the camel proteins, may play a beneficial role in human health once they are released from milk either in vivo during normal digestion or by proteolysis with purified enzymes or during bacterial fermentation. Similar to the bovine milk counterparts, camel milk bioactive peptides may display a variety of potential activities that were almost always unveiled from in vitro analyses: anti-microbial, anti-oxidative, anti-hypertensive, anti-inflammatory, and immunomodulatory activities. Today, there is a growing interest for bioactive peptides generated from camel milk. This paper reviews available data on the potential biological activities of the camel milk proteins and their peptides liberated either during milk fermentation with proteolytic bacterial strains or by enzyme hydrolysis with specific proteases or simulated gastro-intestinal digestion.     

Mild processing of seafood—A review

Recent years have shown a tremendous increase in consumer demands for healthy, natural, high-quality convenience foods, especially within the fish and seafood sector. Traditional processing technologies such as drying or extensive heating can cause deterioration of nutrients and sensory quality uncompilable with these demands. This has led to development of many novel processing technologies, which include several mild technologies. The present review highlights the potential of mild thermal, and nonthermal physical, and chemical technologies, either used alone or in combination, to obtain safe seafood products with good shelf life and preference among consumers. Moreover, applications and limitations are discussed to provide a clear view of the potential for future development and applications. Some of the reviewed technologies, or combinations thereof, have shown great potential for non-seafood products, yet data are missing for fish and seafood in general. The present paper visualizes these knowledge gaps and the potential for new technology developments in the seafood sector. Among identified gaps, the combination of mild heating (e.g., sous vide or microwave) with more novel technologies such as pulsed electric field, pulsed light, soluble gas stabilization, cold plasma, or Ohmic heat must be highlighted. However, before industrial applications are available, more research is needed.     

Bioactive principles from Cordyceps sinensis: A potent food supplement – A review

Cordyceps sinensis (CS) is a well-known entamophagus fungus, naturally distributed in the Tibetan Plateau of Asia and Himalayas. Recently this synonym is transferred to Ophiocordyceps by both scientific and non-scientific communities. It is widely used as a tonic and medicinal food in traditional Chinese medicine (TCM), as it possess wonderful health benefits. To support its functional attributes, various investigations have been carried out to find out its adaptogenic, aphrodisiac, anti-oxidant, anti-aging, neuroprotective, nootropic, immunomodulatory, anti-cancer and hepatoprotective role. Its fruiting portion as well as the larvae possesses potent bio-active fractions and their composition almost found to be similar in both. The bioactive principles are nucleosides, exo-polysaccharides, sterols and, proteins, among others. Among nucleosides, adenosine and cordycepin are the major biochemical markers. Further, different types of solvent extracts and their mixtures exhibit wide range of pharmacological activities, while the water and methanol extracts with the richest sources of nucleosides and polysaccharides also show wide range of pharmacological activities. This review gives a panoramic view of potential health benefits of various classes of bio-active fractions along with the need for sustainable management of CS for human wellness.     

Olive oil and its principal bioactive compound: Hydroxytyrosol – A review of the recent literature

BackgroundOlive (Olea europaea L.) oil is one of the main ingredients of the Mediterranean diets and as such, it is considered responsible for the overall well being of the Mediterranean populations. With European Food Safety Authority (EFSA) approving the health claims of olive oil in part due to the presence of hydroxytyrosol (HT), there is a global upsurge in the exploration of the different health promoting and disease preventing abilities of this bioactive compound.Scope and approachBesides presenting an overview of the fatty acid and phenolic (minor) profiles of olive oil, the present article reviews the nutraceutical properties of olive oil attributed to the presence of HT, health promoting and disease preventing abilities of pure HT, and the synthesis of HT and its metabolic derivatives of biological interests.Key findings and conclusionsOlive oil contains high profile fatty acids and phenolics. The fatty acid profile changes with maturation of the olives. Oleic acid predominates throughout the maturation period. Palmitic acid is predominantly found in the unripe stage while as, palmitoleic acid, stearic acid, and linoleic acid are chiefly found in ripe olives. Oleuropein is the predominant secoiridoid in the early stages of olive maturation. As the maturation proceeds, oleuropein degrades to yield HT. Over the years, HT has been explored against a number of health complications and shows promising results against diabetes, inflammation, nervous disorders, angiogenesis, cancer, oxidative stress, heavy metal toxicity, hemolysis, LDL oxidation, muscle damage, and nephrotoxicity. The bioactive properties of HT are accomplished through nutrigenomic and immunomodulatory mechanisms. HT, its lipophilic derivatives, and many of its metabolites of biological interests have been synthesized through microbological, biotechnological, and other chemical strategies.     

Recovery of carotenoids from tomato processing by-products – a review

Industrial tomato processing generates large amount of low-value by-products, primarily used as livestock feed or disposed of; however, being a rich source of natural carotenoids, tomato waste can be used to produce high value-added products for food, cosmetics, or pharmaceutical applications. The objective of this review is to summarize and give an overview of the extraction methods available for the recovery of carotenoids and, especially, lycopene from tomato processing by-products. Organic solvent extraction techniques are presented and the effect of extraction conditions on carotenoids recovery is evaluated. In particular, the use of Ultrasound Assisted (UAE), Microwave Assisted (MAE), Enzyme-Assisted (EAE) and Extraction at High Pressure (HPE) for the recovery of carotenoids is assessed. Also, this review examines the efficiency of Supercritical Fluid Extraction (SFE) and in particular the effect of process parameters on carotenoid recovery from industrial tomato waste.