Combination of ohmic heating and subcritical water to recover amino acids from poultry slaughterhouse waste at a pilot-scale: new valorization technique.

Considering the global need for waste valorization and enhancing resource efficiency, this study investigated the possibility of recovering amino acids from underutilized chicken heads and legs as poultry by-products. In this sense, a new combined technique was developed based on ohmic heating (OH) and subcritical water (SCW), i.e., OHSCW. Besides, the effects of OH at different electric field strengths (5.71, 7.14, and 8.57 V/cm) and times (15, 30, and 45 min) were compared with the control treatment (SCW equipped with conventional heating, without OH) at a temperature of 140 °C. The results showed that the come-up time using OHSCW, at electric field strengths of 7.14 and 8.57 V/cm, was less than the control method by 17 and 75%, respectively. The lowest specific energy consumption was 403.68 kJ/kg which was 59.22% less than the control method. The highest energy efficiency was 93.88% at the electric field strength of 8.57 V/cm which was superior to that of the control treatment, i.e., 47.13%. The amounts of total amino acids recovered by OHSCW, at an electric field strength of 8.57 V/cm, were higher than the control method by 70.48%. OHSCW at an electric field strength of 5.71 V/cm yielded the maximum recovery efficiency of amino acids (79.40%) while recovery efficiency in control treatment was 15.48%. Besides, the results of Amino acid Analyzer (AAA) showed that the recovered amino acids include asparagine, serine, glutamine, glycine, threonine, histidine, cysteine, alanine, aspartic, tryptophan, arginine, tyrosine, valine, methionine, isoleucine, leucine, and phenylalanine. Supplementary Information: The online version contains supplementary material available at 10.1007/s13197-022-05556-4.

Enhancing Bioactive Saponin Content of Raphanus sativus Extract by Thermal Processing at Various Conditions.

Pickled radish (Raphanus sativus) is a traditional Asian ingredient, but the traditional method takes decades to make this product. To optimize such a process, this study compared the saponin content of pickled radishes with different thermal processing and traditional processes (production time of 7 days, 10 years, and 20 years) and evaluated the effects of different thermal processes on the formation of radish saponin through kinetics study and mass spectrometry. The results showed that increasing the pickling time enhanced the formation of saponin in commercial pickled radishes (25 °C, 7 days, 6.50 ± 1.46 mg g-1; 3650 days, 23.11 ± 1.22 mg g-1), but these increases were lower than those induced by thermal processing (70 °C 30 days 24.24 ± 1.01 mg g-1). However, it was found that the pickling time of more than 10 years and the processing temperature of more than 80 °C reduce the saponin content. Liquid chromatography-mass spectrometry (LC-MS) analysis showed that the major saponin in untreated radish was Tupistroside G, whereas treated samples contained Asparagoside A and Timosaponin A1. Moreover, this study elucidated the chemical structure of saponins in TPR. The findings indicated that thermal treatment could induce functional saponin conversion in plants, and such a mechanism can also be used to improve the health efficacy of plant-based crops.

The Impact of Different Pretreatment Processes (Freezing, Ultrasound and High Pressure) on the Sensory and Functional Properties of Black Garlic (Allium sativum L.).

Black garlic (BG) is an emerging derivative of fresh garlic with enhanced nutritional properties. This study aimed to develop functional BG products with good consumer acceptance. To this end, BG was treated with freezing (F-BG), ultrasound (U-BG), and HHP (H-BG) to assess its sensory and functional properties. The results showed that F-BG and H-BG had higher S-allyl-cysteine (SAC), polyphenol, and flavonoid contents than BG. H-BG and F-BG displayed the best sensory quality after 18 days of aging, while 5-hydroxymethylfurfural (5-HMF), SAC, and polyphenols were identified as the most influential sensory parameters. Moreover, the F-BG and H-BG groups achieved optimal taste after 18 days, as opposed to untreated BG, which needed more than 24 days. Therefore, the proposed approaches significantly reduced the processing time while enhancing the physical, sensory, and functional properties of BG. In conclusion, freezing and HHP techniques may be considered promising pretreatments to develop BG products with good functional and sensory properties.

Pilot-scale ohmic heating-assisted extraction of wheat bran bioactive compounds: Effects of the extract on corn oil stability.

Recent studies introduced ohmic heating-assisted extraction (OHAE) as a promising emerging technology at laboratory-scales. The objectives of the present study were, first, to investigate the applicability of OHAE at pilot-scale for extraction of bioactive compounds from wheat bran immersed in a polar solvent (salted water containing 0.1% NaCl) at the electric field strengths (EFS) of 4.28, 7.90, and 15.71 V/cm and, second, to evaluate the effects of the wheat extracts on the corn oil stability during 30 days of storage at 45 °C. The results showed that OHAE saved 63% of energy consumption compared with the conventional extraction method. Also, the scaled-up OHAE unit yielded extracts with high quantities of bioactive compounds (110-460 ppm total phenolics) and higher antioxidant activities (antioxidant effectiveness of 56-84%) than those of the extract obtained through the conventional extraction method, i.e., 95 ppm total phenolics with antioxidant effectiveness of 51%. Increasing the EFS increased total phenolics and antioxidant effectiveness of extracts. The incorporation of 250 ppm of the extract obtained at the highest EFS effectively postponed the oxidation of corn oil during one month of storage (peroxide value of 7 vs. 19 meq/kg compared with the control sample) and extended the half-life of oil from 11 to 26 days. Besides, mathematical models proposed in this study well-predicted the oxidation stability of the oil samples mixed with the extract.

Impact of ultrasound-assisted extraction and solvent composition on bioactive compounds and in vitro biological activities of thyme and rosemary.

Mediterranean herbs, specially thyme and rosemary, are important ingredients in food preparation and more recently have been studied as natural sources of bioactive compounds. This study aimed to study the effect of matrix (thyme vs. rosemary), and extraction protocol (conventional extraction vs. ultrasound assisted extraction) solvent composition (water vs. 50:50 ethanol:water solution) on the extraction of high value compounds (phenolic compounds, flavonoids and carotenoids) and also explore the antioxidant, antimicrobial (Listeria innocua, Staphylococcus aureus, and Salmonella enterica), probiotic (Lactobacillus casei and Bifidobacterium lactis), and anti-inflammatory activities. The phenolic, flavonoid and carotenoid content of extracts was greatly influenced by extraction conditions wherein the ultrasound pre-treatment improved the extraction of carotenoids but induced the opposite effect for polyphenols and flavonoids in both herbs. Only the aqueous extract of thyme obtained from ultrasound pre-treatment was the only extract that inhibited the growth of potentially pathogenic bacteria, stimulated the probiotic bacteria and achieved high anti-inflammatory and antioxidant activity. Moreover, this extract also was rich on phenolic compounds (such as p-coumaric acid 4-O-glucoside, kaempferol 3-O-rutinoside, feruloyl glucose, and 4-vinylguaiacol) and carotenoids. Therefore, ultrasound extraction of bioactive compounds with water as solvent could be explored in food and pharmaceutical applications.

Aquaculture and its by-products as a source of nutrients and bioactive compounds.

Underutilized marine resources (e.g., algae, fish, and shellfish processing by-products), as sustainable alternatives to livestock protein and interesting sources of bioactive compounds, have attracted the attention of the researchers. Aquatic products processing industries are growing globally and producing huge amounts of by-products that often discarded as waste. However, recent studies pointed out that marine waste contains several valuable components including high-quality proteins, lipids, minerals, vitamins, enzymes, and bioactive compounds that can be used against cancer and some cardiovascular disorders. Besides, previously conducted studies on algae have shown the presence of some unique biologically active compounds and valuable proteins. Hence, this chapter points out recent advances in this area of research and discusses the importance of aquaculture and fish processing by-products as alternative sources of proteins and bioactive compounds.

Ohmic heating as a promising technique for extraction of herbal essential oils: Understanding mechanisms, recent findings, and associated challenges.

The applicability of ohmic heating, as a volumetric heating technique, has been explored in various sectors of the food industry. The use of ohmic heating for essential oil extraction is among its emerging applications. This chapter overviews the recent progress in this area of research, discusses the mechanisms involved in ohmic-based essential oil extraction processes, explains the effective process parameters, highlights their benefits, and explains the considerations to address the obstacles to industrial implementation. Ohmic-assisted hydrodistillation (OAHD) and ohmic-accelerated steam distillation (OASD) systems were proposed as alternatives to conventional hydrodistillation and steam distillation, respectively. These techniques have successfully extracted essential oils from several aromatic plants (e.g., thyme, peppermint, citronella, and lavender). Both OAHD and OASD possess a number of benefits, such as reducing the extraction time and energy consumption, compared to classical extraction methods. However, these techniques are in their infancy and further economic and upscaling studies are required for their industrial adaptation.

Essential oils as natural preservatives for bakery products: Understanding the mechanisms of action, recent findings, and applications.

Bakery products, as an important part of a healthy diet, are characterized by their limited shelf-life. Microbiological spoilage of these products not only affects the quality characteristics and result in the economic loss but also threatens consumer's health. Incorporation of chemical preservatives, as one of the most conventional preserving techniques, lost its popularity due to the increasing consumer's health awareness. Therefore, the bakery industry is seeking alternatives to harmful antimicrobial agents that can be accepted by health-conscious customers. In this regard, essential oils have been previously used as either a part of product ingredient or a part of the packaging system. Therefore, the antimicrobial aspect of essential oils and their ability in delaying the microbiological spoilage of bakery products have been reviewed. Several types of essential oils, including thyme, cinnamon, oregano, and lemongrass, can inhibit the growth of harmful microorganisms in bakery products, resulting in a product with extended shelf-life and enhanced safety. Research revealed that several bioactive compounds are involved in the antimicrobial activity of essential oils. However, some limitations, such as the possible negative effects of essential oils on sensory parameters, may limit their applications, especially in high concentrations. In this case, they can be used in combination with other preservation techniques such as using appropriate packaging materials. Further research regarding the commercial production of the bakery products formulated with essential oils is required in this area.

Fucus vesiculosus extracts as natural antioxidants for improvement of physicochemical properties and shelf life of pork patties formulated with oleogels.

BACKGROUND: There is limited information in the literature concerning the feasibility of using algal extracts as natural additives for improvement of the quality and shelf-life of meat products. Hence, a Fucus vesiculosus extract (FVE) at the concentrations of 250 mg kg-1 (FVE-250), 500 mg kg-1 (FVE-500) and 1000 mg kg-1 (FVE-1000) were added to pork patties with linseed oil oleogel as a fat replacer. RESULTS: Total polyphenol content of FVE was determined to be 20 g phloroglucinol equivalents 100 g-1 extract. Antioxidant values ranged from 37.5 µmol of Trolox equivalents (TE) g-1 (FRAP assay) to 2111 µmol TE g-1 extract (ABTS assay). Regarding oxidation stability, FVE-1000 showed the lowest values of thiobarbituric acid-reactive substance and carbonyl content. On the other hand, FVE did not improve color, surface discoloration or odor attributes of patties during storage. Sensory evaluation revealed that there was no significant difference among all studied samples. CONCLUSION: Although FVEs have a high polyphenol content and antioxidant activities, they are not effective oxidation inhibitors for long-term storage of meat products. Therefore, additional measures or compounds should be considered when FVE is the only antioxidant in meat products. © 2019 Society of Chemical Industry.

Understanding the potential benefits of thyme and its derived products for food industry and consumer health: From extraction of value-added compounds to the evaluation of bioaccessibility, bioavailability, anti-inflammatory, and antimicrobial activities.

Natural bioactive compounds isolated from several aromatic plants have been studied for centuries due to their unique characteristics that carry great importance in food, and pharmaceutical, and cosmetic industries. For instance, several beneficial activities have been attributed to some specific compounds found in Thymus such as anti-inflammatory, antioxidant, antimicrobial, and antiseptic properties. Moreover, these compounds are classified as Generally Recognized as Safe (GRAS) which means they can be used as an ingrident of may food producs. Conventional extraction processes of these compounds and their derived forms from thyme leaves are well established. Hoewever, they present some important drawbacks such as long extraction time, low yield, high solvent consumption and degradation thermolabile compounds. Therefore, innovative extraction techniques such as ultrasound, microwave, enzyme, ohmic and heat-assisted methods can be useful strategies to enhance the exytraction yield and to reduce processing temperature, extraction time, and energy and solvent consumption. Furthermore, bioaccessibility and bioavailability aspects of these bioactive compounds as well as their metabolic fates are crucial for developing novel functional foods. Additionally, immobilization methods to improve stability, solubility, and the overall bioavailability of these valuable compounds are necessary for their commercial applications. This review aims to give an overall perspective of innovative extraction techniques to extract the targeted compounds with anti-inflammatory and antimicrobial activities. Moreover, the bioaccessi-bility and bioavailability of these compounds before and after processing discussed. In addition, some of the most important characteristics of thyme and their derived products discussed in this paper.

Prevalence and probabilistic health risk assessment of aflatoxins B1, B2, G1, and G2 in Iranian edible oils.

The prevalence of aflatoxins (AFs) B1, B2, G1, and G2 in Iranian edible oils were assessed by immunoaffinity column cleanup and HPLC equipped with a fluorescence detector (HPLC-FLD). Ninety-seven samples including sunflower, canola, refined olive, unrefined olive, frying, and blend oils were collected from eight provinces (n = 15 samples of refined olive oil, n = 15 samples of unrefined olive oil, n = 15 samples of sunflower oil, n = 15 samples of canola oil, n = 17 samples of frying oil, and n = 20 samples of blend oil). Also, cancer risk of aflatoxins in the adults and children due to ingestion of edible oils was estimated via margin of exposure (MOE) estimation in the Monte Carlo simulation (MCS) model. Considering the limit of detection (LOD) of the current study, two unrefined olive oil samples from Zanjan Province were contaminated with AFB2 in the concentrations of 0.2 and 0.4 ng/g while other samples were free from AFB1, AFB2, AFG1, and AFG2. This study revealed that about 98% of the collected samples were free from AFs and the concentrations of AFs in the polluted samples were within the standard range suggested by European Commission regulation (20 µg/kg). However, health risk assessment indicated that both adult and children in the Zanjan Province are at considerable liver cancer risk (percentile 95% of MOE < 10,000 value). Therefore, national plan to address this issue and strict inspection of edible oil products by the regulatory bodies are suggested.

Essential oils as natural additives to prevent oxidation reactions in meat and meat products: A review.

Oxidation reactions during manufacturing, distribution, and storage of meat and meat products result in undesirable physicochemical changes and aromas, which leads to detrimental effects on the product quality. This could be translated into the consumer dissatisfaction and economic loss. One of the most common practices to overcome this issue is the incorporation of synthetic antioxidants. However, the increasing health-consciousness of consumers and their preference for natural additives leads to the search of natural alternatives to synthetic antioxidants. A number of essential oils have strong antioxidant properties and are explored as potential alternatives to chemical antioxidants in the meat industry. These compounds are classified as Generally Recognized as Safe (GRAS), and their application single or combined with other essential oils, ingredients or preservation technologies have beneficial effects on meat products. Their activity depends on several parameters including their concentrations, their possible synergistic effects, and the extraction method used to obtain them. Although steam distillation is the most common industrial technique for essential oils extraction, novel technologies have been emerged to address the drawbacks of the traditional extraction method and to obtain high-quality essential oils. This paper provides an overview of the application of essential oils as potential substitutes for synthetic antioxidants in the meat industry, exploring their mechanism of action against oxidation reactions, and the effect of extraction methods on their effectiveness.