Pods of some Prosopis species are high in sugars, mainly sucrose, and were a major energy source for indigenous people who recognized flavor variations in natural populations and selected trees for flavor. The pleasant cinnamon, cocoa, coffee, hazelnut, and coconut aroma of mesquite flour is due to a variety of pyrazines, sulfur compounds, aldehydes, alcohols, ketones, phenols, lactones and esters. The most important contributors to the odor of mesquite flour are 2,5-dimethyl-3-pyrazine, dimethyl trisulfide, 1-octen-3-ol, 3-penten-2-one, hexanal, 2-methoxyphenol, 5,6-dihydro-6-propyl-2H-pyran-2-one, massoia lactone (5,6-dihydro-6-pentyl-2H-pyran-2-one), 3-methylbutanoic acid, 4-methylphenol, 2-methoxy-4-vinylphenol, γ-nonalactone, methyl cinnamate, 2,3,5-trimethylpyrazine, 2,5-dimethylpyrazine, acetophenone, 2-pentadecanone, dimethyl disulfide, methyl salicylate, benzaldehyde, 3-methylphenol, and 2,6-dimethylpyrazine. Hexanal, a rancidity indicator, was fivefold higher in flours containing seeds. Citric acid concentrations of mesocarp flour ranged between 1.22 and 2.94 g/100 g in P. juliflora, 0.40–0.69 g/100 g in P. alba, and 0.80–0.92 g/100 g in P. pallida and was associated with unpleasant flavor in P. juliflora pods.

This study investigated the potential of isochoric freezing to preserve tomatoes. Isochoric freezing is an emerging technology that preserves biological matter at subfreezing temperatures without any ice damage. Isochoric freezing was compared with freezing under isobaric conditions and with preservation techniques used in the food industry: cold storage at 10 °C and individual quick freezing (IQF). Physicochemical and nutritional properties were evaluated weekly for four weeks. Preservation under isochoric conditions maintained the mass, color, nutrient content (ascorbic acid, lycopene and phenolics) and antioxidant activity of the fresh tomatoes. Also, isochoric preservation led to minimal texture damage. In comparison, mass loss of tomatoes stored at 10 °C for 3 weeks contributed to changes in overall visual quality and firmness as well as significant losses in nutrient content. The greatest mass, texture, and nutrients losses were obtained for tomatoes subjected to IQF and isobaric freezing. The results show that isochoric freezing has the potential to preserve tomatoes while maintaining physicochemical and nutritional properties similar to those of fresh tomatoes which might find application in the commercial preservation of tomatoes.

Summary Efforts are currently directed towards improving the quality of vegetables after freezing and thawing. One of the methods under investigation is isochoric freezing. In this study, we evaluated isochoric freezing for preserving the quality of baby‐leaf spinach. We compared the properties of thawed spinach frozen to −4°C in an isochoric system with those of fresh spinach, thawed spinach frozen to −4°C in an isobaric system and thawed spinach that were commercially frozen. Spinach leaves frozen under isobaric conditions lost mass and thickness, making them softer and translucent. They also lost much of their nutrient content. In comparison, isochoric freezing maintained cell integrity and turgidity. Thawed leaves remained crunchy with characteristics similar to fresh leaves. Isochoric freezing also preserved nutritional content better than isobaric freezing, although significant nutrient losses still occurred.

Due to the perishable nature of fruits and the importance of reducing food waste, an effective preservation technique is required to prolong the shelf life and maintain the physical and nutritional properties of seasonal fruits. In this study, we evaluated isochoric freezing for preserving the quality of sweet cherries. We examined the physical characteristics and nutritional values of thawed cherries frozen to -4 degrees C or -7 degrees C in an isochoric system and compared them with those of fresh cherries, thawed cherries that were individually quick frozen and thawed cherries frozen to -4 degrees C or -7 degrees C in an isobaric system. We found that isochoric freezing decreased the drip loss and better preserved the color, texture, structure, ascorbic acid, phenolic and antioxidant content of frozen cherries, thereby proving their potential in frozen fruit applications.

Lipid oxidation is a very complex and important event causing quality loss of foods, especially those containing highly unsaturated fats. There is growing interest in replacing synthetic antioxidants in food by natural counterparts. Olive leaf is an abundant by-product of the olive oil industry. The aim of this study was to investigate the antioxidant capacity of olive leaf powder (OLP) in minced Atlantic horse mackerel stored at 4 degrees C over 3days. OLP was introduced in the minced at concentrations of 0 (control), 1.5, 3.5, and 4.5%. OLP characterization showed high antioxidant capacity and fiber content. The addition of OLP significantly prevented and delayed minced fish oxidation over storage. The antioxidant effectiveness of OLP was concentration-dependent, as observed in all the parameters analyzed. The results showed OLP as a potential natural antioxidant for fish products. Practical applicationsOlive leaves are an important agrifood by-product produced worldwide. This by-product is valorized for the first time, as far as the authors are aware, as natural antioxidant in fish. Olive leaves are rich in polyphenols (principally oleuropein) and -tocopherol. Consumers may benefit from this research as there is an increasing demand for natural ingredients, along with concern about the environmental effects of food production. The results of the present study suggest that olive leaf powder can be successfully employed as natural ingredient to prevent oxidation in chilled horse mackerel mince. This allows transforming this by-product stream into a commercially valuable antioxidant.

The peels of different pomegranate cultivars (Molla Nepes, Parfianka, Purple Heart, Wonderful and Vkunsyi) were compared in terms of phenolic composition and total phenolics. Analyses were performed on two silica hydride based stationary phases: phenyl and undecanoic acid columns. Quantitation was accomplished by developing a liquid chromatography with mass spectrometry approach for separating different phenolic analytes, initially in the form of reference standards and then with pomegranate extracts. The high-performance liquid chromatography columns used in the separations had the ability to retain a wide polarity range of phenolic analytes, as well as offering beneficial secondary selectivity mechanisms for resolving the isobaric compounds, catechin and epicatechin. The Vkunsyi peel extract had the highest concentration of phenolics (as determined by liquid chromatography with mass spectrometry) and was the only cultivar to contain the important compound punicalagin. The liquid chromatography with mass spectrometry data were compared to the standard total phenolics content as determined by using the Folin-Ciocalteu assay.

Summary Olive mill wastewater ( OMWW ) from 3‐ and 2‐phase mills was subjected to a two‐step membrane filtration process. The obtained reverse osmosis retentate ( RO ‐R) is a phenolic‐rich coproduct stream, and the reverse osmosis permeate is a near‐pure water stream. A pilot‐scale spray dryer was used for the production of RO ‐R powder. The optimum temperature/feed pump conditions were obtained for 3‐phase (150°C/4.4 Hz) and for 2‐phase RO ‐R (175°C/3.8 Hz). The powders obtained by spray drying under these conditions were analysed for physicochemical properties, including identification and quantification of phenolic compounds. Protocatechuic acid, 3‐hydroxytyrosol, tyrosol, vanillic acid and p ‐coumaric acid were quantified in both RO ‐R powders, which show the possibility to obtain a phenolic‐rich powder from an OMWW filtration fraction. This will lead towards better usage of by‐products from olive oil production.

A current trend in olive mill wastewater (OMWW) management is to not only decrease environmental pollution but also to extract and utilize valuable by-products. Therefore, the objectives of this study were to explore different techniques for drying a phenolic-rich membrane filtration fraction of OMWW and compare the techniques in terms of the dried product quality and feasibility of the process. The OMWW from 2 (3-phase and 2-phase) California mills was subjected to a 2-step membrane filtration process using a novel vibratory system. The reverse osmosis retentate (RO-R) is a phenolic-rich coproduct stream, and the reverse osmosis permeate is a near-pure water stream that could be recycled into the milling process. Spray-, freeze-, and infrared-drying were applied to obtain solid material from the RO-R. Drying of the RO-R was made possible only with addition of 10% maltodextrin as a carrier. The total soluble phenolics in dried RO-R were in the range 0.15 to 0.58 mg gallic acid equivalents/g of dry weight for 2-phase RO-R, and 1.38 to 2.17 mg gallic acid equivalents/g of dry weight for the 3-phase RO-R. Spray-dried RO-R from 3-phase OMWW showed remarkable antioxidant activity. Protocatechuic acid, tyrosol, vanillic acid, and p-coumaric acid were quantified in all dried RO-R, whereas 3-hydroxytyrosol was found in 3-phase dried RO-R. This combination of separation and drying technologies helps to add value and shelf-stability to an olive oil by-product and increase environmental sustainability of its production.

Summary Antioxidant activity ( ABTS assay), total phenolics and total anthocyanins were determined in the petioles of twenty‐nine rhubarb ( R heum spp.) varieties. Antioxidant activity ranged from 463 ± 50 ( R heum officinale ) to 1242 ± 2 μmol Trolox per g DW ( V alentine). The phenolic content varied from 673 ± 41 ( L oher B lut) to 4173 ± 23 mg GAE /100 g DW ( P lum H utt) and had a low correlation ( r = 0.663) with antioxidant results. Seven of the varieties ( P lum H utt, V alentine, M innesota N o. 8, C herry R ed, C awood D elight, C oulter M cDonald and OR 23) had higher total phenolics than kale, a vegetable rich in phenolics. The concentration of anthocyanins ranged from 19.8 ± 1.5 ( C rimson R ed) to 341.1 ± 41.6 mg/100 g DW ( V alentine). The percentages of two main anthocyanins in rhubarb, cyanidin 3‐glucoside and cyanidin 3‐rutinoside varied from 66.07:33.93, respectively, in V alentine to 9.36:90.64, respectively, in R. officinale .

Flour from the mesocarp of pods of the tree legume known as mesquite (Prosopis spp.) in North America or algarrobo in South America was one of the most important food staples for desert people. Contemporary milling techniques produce a flour similar to that of indigenous peoples that is about 40% sucrose, 25% dietary fiber, and that has a variety of volatiles, such as 2,6-dimethylpyrazine, gamma-nonalactone, methyl salicylate, and 5,6-dihydro-6-propyl-2H-pyran-2-one, that contribute to a chocolate and coconut-like aroma. Flour made from the mesocarp contains no stachyose or raffinose, sugars that are responsible for flatulence in other legumes. High-performance liquid chromatography (HPLC) analyses of sugar (sucrose) and citric, malic, and ascorbic acids found considerable ranges in acid/sugar ratio that may be responsible for the wide variations in organoleptic perception. Due to the absence of gliadin, peanut, and soy allergens, the flour is useful in gluten-free formulations. Optimum concentrations for incorporation ranged from 5% for biscuits, 10% for breads, 15% for pancakes/muffins, and 50% in chapatti and drum-dried wheat flour. At these concentrations, considerable browning occurs, which is generally considered to be desirable.

Abstract Volatile constituents of Baikal skullcap (Scutellaria baicalensis Georgi) flowers were isolated by solid-phase microextraction (SPME) and analyzed by GC and GC-MS. A total of 64 constituents was identified (constituting 57.1 - 89.9 % of the total area), 13 of which were tentatively identified. β-Caryophyllene (22.3 - 41.5 %), germacrene D (12.4 - 27.5 %), δ-cadinene (3.1 - 5.4 %), γ-muurolene (1.9 - 3.4 %), γ-cadinene (1.6 - 3.1 %), α-humulene (1.6 - 2.6 %), α-copaene (1.4 - 2.3 %), α-muurolene (1.0 - 2.6 %), bicyclogermacrene (1.1 - 2.1 %) and 3-octanone (0.9 - 3.0 %) were the major constituents of the flower volatiles. A small amount (0.5 %) of the uncommon volatile, 2-(methylamino) benzaldehyde was detected in one of the samples.

Mesquite (Prosopis spp.) are woody leguminous plants that belong to the family Leguminosae and grow in and and semiarid regions of America, Africa and Asia. Prosopis spp. produce indehiscent fruit (pods) that can be milled to yield flour that is sold commercially and is used in pastries and baked goods. The major volatile constituent of mesquite flour was identified as 5,6-dihydro-6-propyl-2H-pyran-2-one on the basis of its Kovats index and mass spectrum. Using delta-nonalactone as an internal standard its concentration was determined to be 59.75 +/- 7.07 mg/kg (n = 3). (C) 2008 Elsevier Ltd. All rights reserved.

Volatile constituents of California skullcap (Scutellaria californica A. Gray) flowers were isolated by solid-phase microextraction (SPME) and analyzed by GC and GC/MS. A total of 52 constituents were identified (constituting 90.8% of the total area), 12 of which were tentatively identified. beta-Caryophyllene (56.6%), germacrene D (6.9%), methyl 2-methylbutyrate (4.9%), beta-bourbonene (4.5%), alpha-humulene (2.8%), methyl butyrate (2.7%), and alpha-copaene (1.5%) were the major constituents of the flower volatiles. Due to their low odor thresholds (measured in water) and fruity aroma, methyl 2-methylbutyrate (4.9%; odor threshold = 0.1 ppb) and ethyl 2-methylbutyrate (0.7%; odor threshold = 0.007 ppb) were considered to be important contributors to the characteristic sweet, apple-like odor of these flowers.