Special Issue on “Food Processing Technologies Applied to Cereals, Legumes, Oilseeds, Alternative Food Raw Materials and Their Derivatives”

A significant problem for the food industry is delivering high-quality, healthy food in response to the rising food demands brought on by the expanding worldwide population. To create novel foods, increase their consumer appeal, and increase public awareness, the food industry uses both conventional and unconventional raw ingredients and proposes new or alternative processing technologies. In order to obtain valuable results, food design optimization requires a deep characterization of the influences that these processing techniques could have on the raw matrix.

Proteins are macronutrients of vital importance for human health and metabolism. In the context of the continuous growth of the population and the improvement of living standards, conventional animal protein is no longer sufficient to provide for the daily human demands. Thus, sustainable alternatives to animal protein are sought, and plant proteins are considered good candidates for this replacement. Moreover, plant proteins are friendlier to the environment. Applying adequate processing technologies could lead to the improvement of plant protein techno-functional parameters in order to enhance its applicability in the food production sector. For example, plant proteins typically have low water solubility, which affects other functional properties such as foaming and emulsification. The improvement of these features opens new research opportunities. In this Special Issue, Gao et al. [1] described the extrusion technology used to expand the range of processing and applications for food and feed raw materials. Compared to un-extruded protein, some techno-functional (solubility, water-holding capacity, emulsion stability) properties were improved by extrusion. The authors concluded that extrusion cooking can effectively improve the functional properties of rice protein, enhancing the application of rice protein resources. For instance, rice protein can be used to increase the nutritional value of products such as juice and sports drinks, while the water-holding capacity and nitrogen solubility index have been improved. Moreover, the improvement of the foaming capacity and stability transforms the rice protein into a food additive, while the emulsification and emulsification stability improvements make the rice protein usable in ice cream or dessert production. Heredia-Leza et al. [2] reviewed the use of chemical modifications to plant-based proteins to improve their techno-functional properties when used in food formulations. Enzymatic hydrolysis, acetylation, and succinylation are the most commonly used chemical processes to modify plant protein structure, and the article offers a detailed analysis of their effects on solubility, emulsifying capacity, and foam capacity, along with future prospects for the chemical modification of the proteins. These functional characteristics are the result of the interactions between proteins and water, oil, or air and have an important role in the control of the texture, flavor, or other sensory qualities of a newly developed food product. The literature review revealed that the primary types of plant protein mainly selected for chemical modifications were legumes (54.2%), oilseeds (16.7%), edible seeds, nuts and other sources (25%), while tubers accounted for 4%. Soy protein still holds first place among the matrices used for plant protein modification and has the most applications in food production. Regarding the impact of chemical modification on plant proteins’ digestibility, the author concluded that an assessment of the amino acid profile needs to be performed in order to establish if innovative food could be introduced into the human diet. Additionally, chemical modifications seem to be the practical way to decrease the amount of antinutritional compounds. China and the United States of America are the top two countries for patent protection of novel methods and products based on modified plant proteins.

Innovative food design based on alternative raw materials is also a current research topic, and several groups of researchers report on the topic in this Special Issue. Food 3D printing is an advantageous method with a broad range of applications. Aside from the ability to create complex structures, the technique can also be used to provide innovative foods for consumers with special needs, such as: children, the elderly, and people with particular medical conditions. In this regard, foods with novel texture or with controlled release of nutrients are only few examples. The study conducted by Johansson et al. [3] published in this Special Issue, aimed to combine 3D printing with plant-based constituents to obtain innovative food products from 100% faba bean. For this purpose, faba bean fractions (protein, starch, fibers) were used as components of the edible inks. The influences of the faba bean fractions on the properties of 3D-printed foods were also assessed. The inks were evaluated using small amplitude oscillatory shear measurements, and the freeze-dried 3D-printable food samples were analyzed using compression tests and scanning electron microscopy. The results showed that the textural characteristics of the 3D-printed items were influenced by ink composition. To assess the shape stability through additional post-treatments (oven baking or frying) more research is required. To optimize the product, sensory and customer testing will also be required. Overall, fractions dense in protein, starch and fiber extracted from faba beans can be successfully used in combination with 3D printing for innovative healthy foods.

Rittisak et al. [4] proposed riceberry as a raw material for broken riceberry powder production by using a drum dryer after pregelatinization. The potential of the resultant powder was examined for the development of a novel instant beverage. The drum drying temperatures and drum speeds were selected as influencing factors of the physical, antioxidant and sensory properties of the riceberry powder. The water activity, total color difference, DPPH scavenging activity, water solubility index and water absorption index were examined and the riceberry powder with the optimum parameters was chosen for the development of the instant beverage with high physicochemical, sensorial and microbiological quality. It was concluded that the riceberry powder could be used with good results for this purpose.

In light of the rising interest in health-improving foods, some studies aim to assess the impact of conventional and modern technologies on the bioactive compound content from raw materials. Nowadays, it is well known that oil undergoes significant physical and chemical changes due to seed and oil processing steps, and the concentrations of their bioactive compounds significantly drop. New research to track bioactive retention using current processing techniques is needed. The production of Brassica napus (canola) seeds and the consumption of canola oil has increased worldwide considerably in the last decade. Due to rising customer demand for more natural and healthful food products, oil quality and composition have more recently become significant market drivers. Besides its valuable fatty acid content, canola oil possesses beneficial bioactive properties due to its phytosterol, tocopherol, and carotenoid content. In this Special Issue, Flakelar et al. [5] analyzed the content of phytosterol, tocopherol and carotenoid from Australian canola seeds, press cake, and different oil samples gathered from the major stages of five commercial canola oil processes. The influence of different processing methods was evaluated. Thus, a comparative analysis was made between the samples processed as follows: expeller + solvent extraction with chemical refining, expeller extraction with physical refining, expeller extraction with chemical refining, cold pressing with physical refining and cold pressing with partial refining (bleaching only). The results showed high concentrations of tocopherols and phytosterols in all samples and suggest that modern oil processing techniques could lead to good bioactive potential of the product, even if some factors such as the seed origin, the variety, the seed preparation, and oil extraction conditions also affect this content. Regarding carotenoid retention, especially from selected rich varieties, this research indicates that adequate techniques, such as cold pressing, could be a good way to achieve this goal.

Sunflower oil is also one of the most popular and consumed vegetable oils in the world. However, one of the major issues regarding the use of sunflower oil is oxidative rancidity due to its high content of unsaturated fatty acids. Broadly, the problem is solved in commercial oil by the addition of synthetic antioxidants, but a large number of studies are proposing their replacement with plant-natural antioxidant compounds. There has been a lot of interest in essential oils worldwide, especially due to their aromatic and antioxidant capacity in different food matrices. Fan et al. [6] studied in their research the application of such natural antioxidants. The essential oil extracted from Lonicera japonica flower buds, together with its constituent eugenol were tested in the deep-frying procedure of sunflower oil. The results showed that the essential oil could improve the stability of the sunflower oil during deep-frying at 180 °C for 30 min. Moreover, the study concluded that eugenol was the most important compound with antioxidant effects, and promising results are expected in the future for the replacement of synthetic antioxidants with eugenol.

Another way to obtain health-improved food is to combine raw materials rich in health-promoting molecules with technological procedures widely recognized for their advantages. In this view, Șerban et al. [7] aimed to emphasize the potential of the ancient wheat species (einkorn, spelt, emmer and Khorasan) as promising substitutes for common wheat flour. The superior nutritional composition of the ancient wheat species compared to the modern wheat varieties has transformed these crops into very popular flours among bread producers and consumers. On the other side, the metabolites created during sourdough fermentation have an advantageous effect on the texture of the dough and bread, resulting in a less elastic and softer dough but a firmer and rougher bread crumb. Additionally, the lactic acid bacteria and yeasts contribute significantly to the improvement of the bread’s nutritional value by reducing the phytate content and postprandial glucose levels, increasing the bioavailability of minerals and supplying some exopolysaccharides with prebiotic and antistaling properties. Recent results on the baking properties of ancient wheat species have led to promising applications, particularly when the sourdough technique is used. Thus, the use of ancient wheat species sourdough in breadmaking could lead to innovative healthy bread assortments.

Nevertheless, many studies target the cutting process of agri-food products, a difficult and energy consuming process due to the varied characteristics of food products. In this context, Panainte-Lehăduș et al. [8] proposed a general equation that explains the connections between the cutting equipment’s operating parameters and the energy needed to complete the process. For this purpose, several fruits and vegetables were used to determine the energy required for cutting. Their textural characteristics directly influenced the process. Between other food properties, the product’s moisture affected the cutting energy value in an inversely proportional manner. Additionally, the peeled fruits and vegetables required more cutting energy than the unpeeled products. As a result, the authors of this study obtained two common logarithmic equations that describe the relationship between the cutting energy and the influencing factors such as product texture, cutting speed, and force.