Oxidative Stability, Microbial Safety, and Sensory Properties of Flaxseed (Linum usitatissimum L.) Oil Infused with Spices and Herbs

Kinetic study of thermal degradation of flaxseed oil and moringa oil blends with physico-chemical, oxidative stability index (OSI) and shelf-life prediction

The thermal degradation kinetics of flaxseed oil (FSO) and moringa oil (MO) blends with soyabean oil (SOY; 80%), rice bran oil (RBO; 80%), cotton seed oil (CSO; 80%) and sunflower oil (SFO; 80%) with Rancimat equipment. There was no significant (p ≤ 0.05) difference observed in the specific gravity (SG), density (D), and refractive index (RI) values of the MO and FSO blends, while the rancidity parameters showed the opposite variations. The FTIR spectra showed absorption bands at 966 cm-1, 1097 cm-1, 1160 cm-1, 1217 cm-1, 1377 cm-1, 1464 cm-1, 1743 cm-1, 2945 cm-1, 2852 cm-1 and 3008 cm-1. Oil blends' kinetic degradation (Ea, ΔH, ΔS, A) is represented by the semilogarithmic relationship between the oxidative stability index (OSI) and temperature. The activation energy (Ea) ranged from 77.1 ± 0.21 to 106.9 ± 0.03 kJ/mol and 73.2 ± 0.01 to 104.4 ± 0.02 kJ/mol for flaxseed oil (FSO) and moringa oil (MO) blends, respectively. The enthalpy (ΔH) and entropy (ΔS) ranged from 67.3 to 121.6 kJ/mol, and - 60.2 to - 8.4 J/mol, and 63.55 to 95.59 kJ/mol and - 20.66 to - 4.11 J/mol for FSO blends and MO blends, respectively.

Graphical Abstract

Improving the functionality of virgin and cold-pressed edible vegetable oils: Oxidative stability, sensory acceptability and safety challenges

In recent years, there has been a growing demand for minimally processed foods that offer health benefits and premium sensory characteristics. This trend has led to increased consumption of virgin (VOs) and cold-pressed (CPOs) oils, which are rich sources of bioactive substances. To meet consumer needs for new oil products conferring multi-functional properties over a longer storage period, the scientific community has been revisiting traditional enrichment practices while exploring novel fortification technologies. In the last four years, the interest has been growing faster; an ascending number of annually published studies are about the addition of different plant materials, agri-food by-products, or wastes (intact or extracts) to VOs and CPOs using traditional or innovative fortification processes. Considering this trend, the present review aims to provide an overview and summarize the key findings from relevant papers that were retrieved from extensively searched databases. Our meta-analysis focuses on exposing the most recent trends regarding the exploitation of VOs and CPOs as substrates, the fortification agents and their form of use, as well as the fortification technologies employed. The review critically discusses possible health claim and labeling issues and highlights some chemical and microbial safety concerns along with authenticity issues and gaps in quality specifications that manufacturers have yet to address. All these aspects are examined from the perspective of developing new oil products with well-balanced techno-, senso- and bio-functional characteristics.

The Use of Ultrasound-Assisted Maceration for the Extraction of Carnosic Acid and Carnosol from Sage (Salvia officinalis L.) Directly into Fish Oil

The aim of the study was to examine the effect of ultrasonic maceration (U) on the extraction of carnosic acid (CA) and its derivative-carnosol (C)-directly from sage into fish oil, compared to homogenization-assisted maceration (H). It was shown that the ultrasonic maceration process (U) allowed for obtaining a macerate enriched in carnosic acid (CA) and carnosol (C), also containing rosmarinic acid (RA), total polyphenols, and plant pigments, and showing antioxidant properties (DPPH test). There was no unequivocal difference in the efficiency of extracting ingredients from sage into the oil macerate between U and H, with the use of ultrasound in most cases resulting in a greater extraction of C and less extraction of pigments from sage into the macerate than in H. The highest simultaneous contents of CA (147.5 mg/100 g) and C (42.7 mg/100 g) in the macerate were obtained after 60 min of maceration U when using a higher power (320 W). The amount of determined compounds also depended on the concentration of methanol (methanol; 70% methanol) used for the analysis. The maceration U is a simple, safe, "green method" of obtaining active substances, with a reduced number of steps, enabling an interesting application form of CA and C, e.g., for food or cosmetics.

Composition, processing, and quality control of whole flaxseed products used to fortify foods

Whole flaxseed (flour) as a good source of omega-3 fatty acid and phytochemicals with excellent nutritional and functional attributes has been used to enrich foods for health promotion and disease prevention. However, several limitations and contemporary challenges still impact the development of whole flaxseed (flour)-enriched products on the global market, such as naturally occurring antinutritional factors and entrapment of nutrients within food matrix. Whole flaxseed (flour) with different existing forms could variably alter the techno-functional performance of food matrix, and ultimately affect the edible qualities of fortified food products. The potential interaction mechanism between the subject and object components in fortified products has not been elucidated yet. Hence, in this paper, the physical structure and component changes of flaxseed (flour) by pretreatments coupled with their potential influences on the edible qualities of multiple fortified food products were summarized and analyzed. In addition, several typical food products, including baked, noodle, and dairy products were preferentially selected to investigate the potential influencing mechanisms of flaxseed (flour) on different substrate components. In particular, the altered balance between water absorption of flaxseed protein/gum polysaccharides and the interruption of gluten network, lipid lubrication, lipid-amylose complexes, syneresis, and so forth, were thoroughly elucidated. The overall impact of incorporating whole flaxseed (flour) on the quality and nutritional attributes of fortified food products, coupled with the possible solutions against negative influences are aimed. This paper could provide useful information for expanding the application of whole flaxseed (flour) based on the optimal edible and nutritional properties of fortified food products.

Innovative and Sustainable Technologies to Enhance the Oxidative Stability of Vegetable Oils

To meet consumers’ demand for natural foods, edible oil producers and food processing industries are searching for alternatives to synthetic antioxidants to protect oils against oxidation. Antioxidant compounds extracted from different plant parts (e.g., flowers, leaves, roots, and seeds) or sourced from agri-food industries, including residues left after food processing, attract consumers for their health properties and natural origins. This review, starting from a literature research analysis, highlights the role of natural antioxidants in the protection of edible oils against oxidation, with an emphasis on the emerging and sustainable strategies to preserve oils against oxidative damage. Sustainability and health are the main concerns of food processing industries. In this context, the aim of this review is to highlight the emerging strategies for the enrichment of edible oils with biomolecules or extracts recovered from plant sources. The use of extracts obtained from vegetable wastes and by-products and the blending with oils extracted from various oil-bearing seeds is also pointed out as a sustainable approach. The safety concerns linked to the use of natural antioxidants for human health are also discussed. This review, using a multidisciplinary approach, provides an updated overview of the chemical, technological, sustainability, and safety aspects linked to oil protection.

Plant Extracts for the Control of Listeria monocytogenes in Meat Products

The antimicrobial activity of garlic (Allium sativum L.) and onion (Allium cepa L.) plant active extracts was determined against Listeria monocytogenes in two meat products. Samples of sausages “cacciatore” and cooked ham in vacuum-packaged slices were artificially contaminated, and the presence of Listeria was evaluated during the sausages ripening and throughout the shelf-life of the cooked ham. The test carried out on sausages did not show differences among treated and untreated samples. The antagonistic activity of the plant extracts against the pathogen was probably hidden by the competition from the sausages microbial flora and the pH and the water activity (aw) decrease. On the other hand, the plant extracts determined an initial reduction of about 1.00 log cfu/g of the L. monocytogenes viable count in the cooked ham slices contaminated with 103 cfu/g, but the best result was obtained with the contamination of 102 cfu/g of L. monocytogenes. In addition to the pathogen’s initial decrease, we observed an extension of the lag phase and a reduction of the Listeria growth rate. Considering that the presence of L. monocytogenes during the slicing phase of the cooked ham does not exceed 10 cfu/g, the use of plant extracts can lead to complete pathogen elimination.