Effect of mixing time, freeze-drying and baking on phenolics, anthocyanins and antioxidant capacity of raspberry juice during processing of muffins

BACKGROUND: Consumption of baked products constitutes an important part of a daily breakfast considering that people are continually grabbing meals on the go. Among baked products, muffins rank third in breakfast products and attract a broad range of consumers. Incorporation of red raspberry juice into muffins can add value to the product while preserving health benefits to the consumer. The purpose of this study was to evaluate the effect of mixing time, freeze‐drying and baking on the phenolic and anthocyanin contents and antioxidant capacity of raspberry juice during the preparation of muffins. RESULTS: Freeze‐drying of raspberry batters reduced their phenolic content and antioxidant capacity regardless of mixing time. Non‐freeze‐dried raspberry batter mixed for 5 min had the highest phenolic content (0.88 mg gallic acid equivalent g^?1 dry matter (DM)). Non‐freeze‐dried raspberry muffins had the highest antioxidant capacity (0.041 µmol Trolox equivalent g^?1 DM). Freeze‐dried raspberry batters mixed for 5 and 10 min had the highest anthocyanin content (0.065 mg cyanidin‐3‐glucoside g^?1 DM). Baking reduced the anthocyanin content of both non‐freeze‐dried and freeze‐dried raspberry muffins. CONCLUSION: Despite the reduction in valuable compounds, muffin is a vehicle for the delivery of these compounds. Copyright © 2012 Society of Chemical Industry     

Effect of high hydrostatic pressure pretreatment on flavour and physicochemical properties of freeze-dried carambola slices

Ripe carambolas are hard to store and transport, while freeze-dried ones are easy to store. However, its long production time leads to higher costs. This study shows that high hydrostatic pressure (HHP) treatment could shorten the freeze-drying time of carambola slices. After HHP treatment (25–250 MPa), the drying time of the fresh sample can be shortened by 33.3–44.4% and the distribution of water and pigment in tissues is much uniform. With the increment of the pressure, 2,2-diphenyl-1-picrylhydrazyl (DPPH) and hydroxyl radical scavenging rate are increased. At 250 MPa, the total phenolic content (TPC) increased from 11.34 to 13.36 mg GAE g⁻¹, and the total flavonoid content (TFC) of the control sample was increased from 10.77 to 12.73 mg RE g⁻¹. Compared with the untreated sample, HHP treatment can enhance the flavour and shorten the freeze-drying time. This work guides the application of HHP technology for drying food processing.     

Physicochemical traits and sensory quality of commercial butter produced in the Azores

In the volcanic islands of the Azores archipelago, pasture is available the entire year and affects the composition of bovine milk fat. The composition of cows' milk butter manufactured in this region was evaluated. All brands showed excellent microbiological and oxidative quality. The fatty acid profile range presented a low n-6/n-3 ratio (1.81–3.38), low atherogenic (2.86–3.11) and thrombogenicity (3.27–3.60) indices and reduced cholesterol content (136–143 mg 100 g⁻¹). In addition, Azorean butters have a high content of conjugated linoleic acid (0.44–0.64 mg 100 g⁻¹), β-carotene (0.12–0.17 mg 100 g⁻¹) and α-tocopherol (1.40–2.20 mg 100 g⁻¹). Sensory analysis revealed high scores for appearance, consistency and flavour of all brands. These results indicate that Azorean butters produced from cows’ milk based on grass-feeding have a potentially healthier fat content and a desirable flavour that, associated with its “natural image”, may be promoted for product differentiation.     

New food ingredients from broccoli by-products: physical,chemical and technological properties

Broccoli stems and leaves examined were rich in protein (23.2%, dry weight), fibre (36.5%, dry weight) and polyphenols (11.4 mg gallic acid equivalents g⁻¹). Chlorogenic acid, neochlorogenic acid and quinic acid were the major phenolics found. Broccoli by-products have potential to be developed as differentiated food ingredients by separation. On a dry basis, the pomace and washed pomace fractions were enriched in fibre and had higher water-holding but lower water solubility and emulsifying capacity compared to juice and supernatant from washed pomace, which were enriched in protein. The juice and supernatant had higher polyphenol content and higher antioxidant activity, suggesting that polyphenols were the major contributors to antioxidant activity. For convenience of use, the products may be supplied as packaged powdered ingredients, but this was practical only for broccoli stems and leaves and pomaces as these powders had higher glass transition temperatures than the juice and supernatant fractions.     

Texture profile of fermented rice extracts with probiotic strains and different contents of waxy maize starch,and sensory acceptance of flavoured selected extract

Rice is a staple food for a great part of the world’s population, and its processing generates a great volume of low value by-products, such as bran and broken grains. This work aimed to elaborate fermented rice by-products extracts with probiotic strains and with different waxy maize starch (WMS) contents (0%, 4%, 8%, 12% and 16% w/w), in order to select one with texture profile similar to Greek-style yogurt, and to characterise the chemical composition and sensory acceptance of the selected extract added with artificial strawberry aroma and fresh strawberry syrup. The texture profile of the extract changed with WMS content and the 4% WMS fermented rice by-products extract was the most similar to Greek-style yogurt. The flavoured fermented rice by-products with WMS product presented 72.67% moisture, 2.55% protein, 0.2% lipid, 0.8% ash (340 mg 100 g⁻¹ of potassium), 27.4 µmol Trolox g⁻¹ and 134.74 mg GAE 100 g⁻¹ of phenolic compounds. The flavoured fermented rice by-products extract did not show microbiological risk and presented probiotic characteristic. Regarding the sensory analysis, it was observed that the aroma stood out among the other attributes, obtaining the highest score and acceptance index, while colour, flavour and texture scored ‘liked regularly to moderately’. The flavoured fermented rice by-products extract is an innovative product and feasible regarding the technological, physical, chemical, microbiological and sensory characteristics, having great potential to be inserted into the market.     

Non-volatile components of several medicinal mushrooms

Three species of medicinal mushrooms are commercially available in Taiwan, including Ling Chih (Ganoderma lucidum), Sung Shan Ling Chih (Ganoderma tsugae) and Yun Chih (Coriolus versicolor). The objective of this study was to examine the non-volatile components in these medicinal mushrooms, including their proximate compositions, soluble sugars, free amino acids and 5′-nucleotides. Ganoderma spp. contained 7.18–7.92% of proteins and Yun Chih contained 4.20%. Carbohydrate contents showed two different levels, Yun Chih (65.09%) and Ganoderma spp. (21.83–27.78%). The fiber contents were in the order of Sung Shan Ling Chih (65.29%), regular and antler Ling Chih (59.16 and 59.49%, respectively), and Yun Chih (23.24%). Yun Chih contained 20.21 mg g⁻¹ dry weight of total soluble sugars whereas Ganoderma spp. contained low amounts. Total free amino acid contents ranged from 4.25 to 14.04 mg g⁻¹. Contents of MSG-like components ranged from 0.17 to 0.50 mg g⁻¹ and sweet components ranged from 0.28 to 1.38 mg g⁻¹. The bitter components were predominantly present in these mushrooms. Contents of total and flavour 5′-nucleotides were high in Yun Chih and Ling Chih. The umami intensities were expected to be in the descending order of Ling Chih, Yun Chih, Sung Shan Ling Chih and antler Ling Chih.     

Effects of α-, β- and maltosyl-β-cyclodextrins use on the glucoraphanin–sulforaphane system of broccoli juice

Cyclodextrins (CDs) are macromolecules with several industrial applications, being particularly used in the food industry as health-promoting compounds protection agents, as flavour stabilizers, or to eliminate undesired tastes and browning reactions, among others. This study shows the effects of α- (10, 30 and 40 mmol L⁻¹), β- (3, 6 and 10 mmol L⁻¹) and maltosyl-β-CDs (30, 60 and 90 mmol L⁻¹) use on the health-promoting glucoraphanin–sulforaphane system of a broccoli juice up to 24 h at 22 °C. Maltosyl-β-CD (90 mmol L⁻¹) highly retained glucoraphanin content after 24 h at 22 °C, showing better effectiveness than β-CD (10 mmol L⁻¹). Sulforaphane was efficiently encapsulated with β-CD at just 3 mmol L⁻¹, and the sulforaphane formed was stable during 3 h at 22 °C. On the other hand, 40 mmol L⁻¹ α-CD retained a high glucoraphanin content in broccoli juice. In contrast, glucoraphanin levels in juice without CDs decreased by 71% after 24 h. Consequently, CDs addition may potentially preserve glucoraphanin in this broccoli juice during industrial processing with the possibility to be later transformed by endogenous myrosinase after ingestion to the health-promoting sulforaphane. © 2018 Society of Chemical Industry     

An improved analytical method for determination of trans-resveratrol and related stilbenes in grape skin by QuEChERS coupled with HPLC-PDA-MS

Grape is a popular fruit crop that generates about one-fourth of total weight as pomace during winemaking and commercial juice production. However, a significant amount of resveratrol and related stilbenes is present in grape skin, and their effective isolation enables the production of functional foods. Herein, an improved analytical method for the determination of trans-resveratrol and related stilbenes in grape skin waste by QuEChERS method coupled with a high-performance liquid chromatograph-photodiode array detector-mass spectrometer was developed. By employing a Gemini C18 column and a mobile phase of acetic acid in water (pH 3.6) and acetonitrile, a total of five resveratrol and related stilbenes could be separated within 15 min with a flow rate of 0.8 mL min⁻¹ and detection wavelength at 306 nm. The optimised QuEChERS conditions were 10 mL of acetonitrile, 1 mL of grape skin extract and 900 mg of magnesium sulphate plus 25 mg of primary secondary amine. Principal component analysis by two principal components (74.18%, 25.82%) could well describe the trans-resveratrol recovery at different QuEChERS conditions. A mean recovery, as well as coefficient of variation (CV, %) of repeatability and intermediate precision, ranged from 96.6% to 104.4%, 1.96% to 3.10% and 1.68% to 4.27%, respectively, conforming to the regulation set by Taiwan Food and Drug Administration. Quantitation revealed cis-piceid to be present in largest amount (2.616 μg mL⁻¹), followed by trans-piceid (1.027 μg mL⁻¹), trans-resveratrol (0.967 μg mL⁻¹), ε-viniferin (0.660 μg mL⁻¹) and cis-resveratrol (0.183 μg mL⁻¹) in grape skin extract, with their corresponding contents in dried grape skin being 4.185, 1.643, 1.539, 1.056 and 0.293 μg g⁻¹, respectively.     

Dynamics of the loss and emergence of volatile compounds during the concentration of cashew apple juice (Anacardium occidentale L.) and the impact on juice sensory quality

Concentrating cashew apple juice alters the beverage aroma and flavor, compromising consumer acceptability of the concentrated beverage. To understand the mechanisms involved in these changes, this research characterized the dynamics of the loss and emergence of volatile compounds during cashew apple juice concentration, reporting their impact on beverage sensory quality. Fresh cashew apple juice (10.3°Brix) was concentrated in a thermal-siphon type evaporator operating in a closed system. Five samples were taken throughout the concentration process with the following soluble solids contents: 11.8°Brix, 14.9°Brix, 20.2°Brix, 29.6°Brix and 42.1°Brix. Trained judges rated the aroma note intensities, described as “fresh cashew apple” and “cooked” as perceived in the fresh and concentrated beverages. The headspace volatiles of the six samples were identified and quantified by GC–MS. The results indicated the esters as the major component in the fresh juice (226.46 μg kg^− 1) representing 45.0% of the total mass of volatiles, followed by the terpenes (118.98 μg kg^− 1), acids (45.23 μg kg^− 1), aldehydes (39.10 μg kg^− 1), alcohols (18.91 μg kg^− 1), lactones (19.15 μg kg^− 1), hydrocarbons (18.02 μg kg^− 1) and ketones (11.05 μg kg^− 1). Predictive statistical models (R² > 0.956, p ≤ 0.002) revealed that on reaching 14.9°Brix, the ester concentration declined more than 90%, the terpene content almost 100%, alcohols 85%, aldehydes 80% and hydrocarbons 90%. At 14.9°Brix, the intensity of “fresh cashew apple” aroma still predominated in the juice, but the panelists detected the presence of a weak “cooked” aroma. Concentration of the beverage to 20.2°Brix or above expressively increased the cooked aroma intensity and the concentration of hydrocarbons, alcohols and some aldehydes usually associated with off-flavors such as pentanal and decanal. This raises the possibility that some of these compounds might have been formed during juice processing. Juice with better sensory quality could possibly be obtained by concentrating the beverage to levels below 20.2°Brix, recovering the esters that evaporated off the juice until ~ 15°Brix is reached, and re-adding them to the juice concentrated.     

树莓澄清果汁的加工工艺

研究了红树莓澄清果汁的加工工艺,酶解处理的酶用量,酶解温度,酶解时间的单因素试验以及酶用量,酶解时间和红树莓品种的正交优化试验表明,树莓果浆经酶解后,出汁率有较大提高,果汁澄清度也较好。最佳酶处理条件为加酶量3.5‰,酶处理温度45℃,时间4h;在所试验的3个品种中,维拉米综合指标最好,表现为出汁率高,可溶性固形物,总糖,VC含量均较高;树莓汁调配时一般不需加酸,只需补充糖即可达到较好的口感风味。     

Non-volatile taste components of several commercial mushrooms

Winter (strains white and yellow), shiitake (strains 271 and Taichung 1) and oyster mushrooms (abalone and tree oyster mushrooms) were collected from commercial sources. Strain yellow contained 26.7% of proteins (higher than other mushrooms). Shiitake and the two oyster mushrooms contained more than 60% of carbohydrates. Arabitol was found in the highest amounts only in winter mushrooms. Glucose, mannitol and trehalose were found in varied amounts. Total soluble sugar contents were in the order: winter mushrooms>shiitake>abalone and tree oyster mushrooms. Total contents of free amino acids also varied and ranged from 4.08 to 31.5 mg g⁻¹ dry weight. Contents of total 5′-nucleotides were similar in the two winter mushrooms, whereas the content of flavour 5′-nucleotides was higher in strain white. Contents of total and flavour 5′-nucleotides were higher in strain 271 than in strain Tainung 1. The two oyster mushrooms were comparable in contents of flavour 5′-nucleotides. The umami taste was in the order: strain 271>winter mushrooms>two oyster mushrooms and strain Tainung 1.     

Identification and quantification of phenolic compounds in kernels,oil and bagasse pellets of common walnut (Juglans regia L.)

Individual phenolic compounds, total phenolic content and antioxidant potential were assessed in kernels, oils and bagasse pellets (residues of oil pressing) of different walnut cultivars. Twenty-seven phenolic compounds were detected in kernels and pellets conducting high-performance liquid chromatography–tandem mass spectrometry. The main polyphenolic subclass comprised hydrolysable tannins, which accounted approximately 60.80% (kernels) and 61.66% (pellets) of the total phenolics identified (TPI). Walnut oil was poor in phenolics and contained only six different compounds but due to their low content (from 0.15 to 1.44 μg g^− 1) just two compounds have been identified. Glansreginin A and glansreginin B were detected in all analyzed walnut products. A comparison of average amount of total phenolic content revealed that walnut oil contains as much as 154 fold less phenolics (0.05 mg GAE g^− 1 FW) compared to kernels (7.7 mg GAE g^− 1 FW) or pellets (7.9 mg GAE g^− 1 FW).     

Combination of freeze drying and molecular inclusion techniques improves the bioaccessibility of microencapsulated anthocyanins from black rice (Oryza sativa L.) and lavender (Lavandula angustifolia L.) essential oils in a model food system

Black rice and lavender are promising sources of bioactives, in terms of anthocyanins and essential oils. Their bioaccessibility were improved by microencapsulation, followed by mixing in order to benefit both from colour and flavour, along with radical scavenging and biological properties. The mixed powder showed a satisfactory anthocyanins of 2.55 mg g⁻¹ DW, leading to a radical scavenging activity of 65.14 mmol g⁻¹ DW. The powder displayed an inhibitory effect against α-glucosidase (~49%) and α-amylase (39%), respectively, with a controlled release in intestinal environment. To further examine the functional properties, the powder was added to a food model system. During storage, a release in anthocyanins and flavonoids were found, leading to an increase in radical scavenging activity. The sensorial analysis showed that supplemented biscuits were appreciated for colour and lavender aroma. The obtained results were promising in tailoring the health benefits of secondary metabolites, underutilised in human’s nutrition due to their low stability and bioavailability.     

A review of limonin in grapefruit (Citrus paradisi) juice,its relationship to flavour,and efforts to reduce it

Ever since limonin was first discovered in grapefruit (Citrus paradisi Macf) juice in 1965 and found responsible for significantly contributing to bitterness in the juice, a great deal of research has been directed towards understanding its role therein. Information is presented relative to limonin's chemical determination, taste threshold and content in grapefruit juice, and to relevant legislation. Also considered are (1) several factors affecting the limonin content of grapefruit juice (2) the effect of limonin content on sensory flavour in grapefruit juice (3) the interaction between the Brix: acid ratio and limonin content in affecting grapefruit juice flavour and (4) methods for reducing limonin in citrus juices generally. Finally, recommendations for future studies on limonin in grapefruit juice are reviewed.     

Extract of Salicornia europaea in fresh pasta to enhance phenolic compounds and antioxidant activity

Extract from Salicornia europaea was added to durum wheat fresh pasta. Sensory properties, cooking quality, microbiological stability, content in bioactive compounds and antioxidant activity, before and after pasta digestion were studied. The extract was obtained by ultrasound-assisted extraction. From the technological point of view the extract did not affect pasta dough and the cooking parameters and sensory properties of the enriched samples were found similar to the control pasta. No antimicrobial effect was exerted by the extract. From the chemical point of view interesting findings were recorded for pasta before and after digestion. Specifically, data of bioaccessible fraction of digested sample showed a significantly higher amount of total phenols and flavonoid content (11.52 mg gallic acid g⁻¹ and 0.55 mg quercetin g⁻¹ respectively) than digested control pasta (9.54 mg gallic acid g⁻¹ and 0.23 mg quercetin g⁻¹ respectively). The antioxidant activity of enriched sample also increased compared to the control pasta (6.20 vs. 2.50 μmoles FeSO₄ g⁻¹).     

Chemical,rheological and sensory characteristics of sweet spreads made from by-products of soya bean and maize

Sweet maize cob (SMC) and black soya bean seed coat (BSC) were used to prepare a sweet spread. Chemical composition of the prepared spread and its rheological and sensory characteristics were investigated. The results were compared with those of commercial plum and raspberry jams and spreads. Spreads made from SMC and BSC had the highest content of proteins, total fibres, hemicellulose and cellulose. In relation to fruit jams, they are distinguished by the presence and content of p-coumaric, ferulic and 3,4-dihydroxybenzoic acids, as well as of flavonoids such as catechin and quercetin. SMC spread with 3.2% of BSC had the highest content of total anthocyanins (666.75 mg CGE kg⁻¹) (cyanidin 3-glucoside equivalent). Cyanidin-3-glucoside (Cy-3-Glu) was the most abundant anthocyanins in SMC/BSC containing spreads, while in raspberry jam, that was cyanidin-3-sophoroside (Cy-3-Sop). According to chemical, rheological and sensory properties, SMC/BSC containing spreads could be competitive with fruit jams and spreads.     

Concentrating sulphur-containing flavour from Toona sinensis shoots using corn oil with and without aqueous dispersion

Toona sinensis (TS) shoot is a seasonal and quick deteriorating vegetable with unique alliaceous flavour. In this study, corn oil was used to concentrate the sulphur-containing compounds responsible for the unique TS flavour with and without aqueous dispersion. The level of sulphur-containing compounds in TS shoots was 0.32 μg g⁻¹ and concentrated to 2.34 μg g⁻¹ in the corn oil with aqueous dispersion. The sulphur-containing compounds, trans-2-Mercapto-3,4-dimethyl-2,3-dihydrothiophene and (E,Z)-Di-1-propenyldisulphide, were identified in the corn oil, while they were not detected in the oil without aqueous dispersion. Based on sensory and electronic nose analysis, the aroma of corn oil with aqueous medium extraction had stronger alliaceous aroma than TS shoots and the extraction corn oil without aqueous dispersion. With aqueous dispersion assistance, the sulphur-containing aroma compounds in TS shoots were effectively concentrated in corn oil. The flavour-enriched oil could serve as a flavour ingredient to deliver TS shoots aroma for different food applications.     

4种柑桔汁的缓冲能力与氮及灰分的二元线性回归关系

果汁含量是果汁的一项重要指标,但目前果汁含量检测方法还不完善,即使有一些检测方法,检测手段也比较繁琐、费时,同时费用较高。对于同一种果汁而言,果汁缓冲能力与果汁的含量呈线性相关关系,但同一类水果不同品种之间缓冲能力是否存在差异以及缓冲能力与水果的那些内在指标密切相关还不清楚。作者选择了南丰蜜桔,砂糖橘、皇帝柑和平远脐橙4种柑桔类水果,制备了相应的柑桔汁,并分别采用检测添加柠檬酸后H+浓度变化的方法检测了其果汁的缓冲系数,采用凯氏定氮法检测了其果汁中氮含量,采用灰化法检测了其灰分质量分数,结果显示这4种柑桔汁缓冲系数与氮含量和灰分呈二元线性相关,回归方程的建立能为利用缓冲能力检测果汁含量的方法提供理论依据。     

The levels of S-alk(en)yl-L-cysteine sulphoxides during the growth of the onion (Allium cepa l.)

Flavour precursors, the S-alk(en)yl-L -cysteine sulphoxides, change considerably in both concentration and total amount during the growth of onions. For the brown onion cv. Pukekohe Long Keeper (PLK) and for the white onion cv. Dehyso, (±)-S-1-propyl-L -cysteine sulphoxide (±PCSO) is the predominant flavour precursor, with (±)-trans-S-1-propenyl-L -cysteine sulphoxide (±PECSO) and (±)-S-1-methyl-L -cysteine sulphoxide (±MCSO) in a minor role. For PLK the greatest concentration of all three precursors is just prior to bulbing (3.6±1.1 mg g^?1 fresh weight); for Dehyso the greatest concentration is at bulbing (4.6±0.6 mg g^?1 fresh weight); Both varieties show a mid-season reduction in flavour precursor concentration (of about 45%), followed by a small but significant increase in ±PCSO concentration during the end of season leaf die-down. The total amount of the three flavour precursors per bulb in both varieties shows a maximum in late January (360±107 mg for PLK, 602±144 mg for Dehyso). In the subsequent months there is a dramatic reduction in the total amount of ±PECSO and ±MCSO, and a slight reduction in ±PCSO. Both varieties show an increase in the amount of ±PCSO at leaf die-down. The relative proportions of these flavour precursors change with bulb age and cultivar. These results suggest that white onions used for drying and processing could be harvested from bulbing onwards. Furthermore, when onion cultivars and onion plant selections are assessed for flavour, care needs to be given to the stage of maturity of the onion.     

The dehydration,shelf-life and potential uses of citrus pulps

Technological treatments and drying conditions for citrus pulp, which accounts for 10–20% of the refuse from citrus juice plants, were established.Washed and unwashed pulp with 5 and 15% total solids (respectively) and partly washed material containing peel, with about 10% solids, served as raw materials. The flakes obtained from a drum drier (at about 4% moisture content) were non-uniform and had low bulk density. Water holding capacity was up to ten times their weight. Drying ratios of 7:1 and 18:1 depending on the total solid content of the raw material, and drying rates of 15–22 kg h^?1 m^?2 dry material were obtained on a pilot double drum drier.Antioxidants added prior to drying prevented fading and development of rancidity during storage. The drum dried product, kept in darkness, at temperatures below 25°C, maintained good colour, flavour and flowability for over a year.Substituting some of the flour, in Snap cookies and yeast cake, with citrus fibres showed they could serve as binding and filling agents. Sensory evaluation of these products showed those with levels up to 7·5% fibres (containing peel) and 20% fibres (without peel) were tasty.