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UV-C (180–280 nm) has been shown to extend the postharvest shelf-life of many horticulture crops. In this study, Tahitian limes (Citrus latifolia) were exposed to 0, 3.4, 7.2 and 10.5 kJ m(−2) UV-C then stored for 28 days in air at 10 °C and 80% RH. Weight loss, peel colour, calyx abscission, ethylene production, respiration rate, total soluble solids (TSS), titratable acidity (TA) and acceptability index were assessed. The results showed that UV-C treatment maintained lime peel green colour and retained calyx attachment after 28 days storage. UV-C treatment also affected endogenous ethylene production and respiration rate, where the highest UV-C treatment (10.5 kJ m(−2)) maintained low ethylene production and low respiration rates after 28 days storage with no differences between the different UV-C intensities. In terms of fruit acceptability, limes were exposed to 10.5 kJ m(−2) UV-C had a 60% acceptability index after 28 days storage, while untreated control fruit retained acceptability of 39%. In general, the pre-storage UV-C treatments did not affect fruit weight loss, TSS or TA contents during storage.

A rice starch edible coating blended with sucrose esters was developed for controlling the postharvest physiological activity of Cavendish banana to extend postharvest quality during ripening at 20 ± 2 °C. Coating effectiveness was assessed against changes in fruit physiochemical parameters such as weight loss, titratable acidity, total soluble solids, flesh fruit firmness, ion leakage, colour change, respiration, ethylene production, chlorophyll degradation and starch conversion were determined. The topography of coating material on the fruit surface was evaluated by scanning electron microscope (SEM). Surface morphology studies highlighted the binding compatibility of the coating matrix with the fruit peel character and formed a continuous uniform layer over the fruit surface. The results showed that the coating was effective in delaying ethylene biosynthesis and reducing respiration rate. Other factors impacting included delayed chlorophyll degradation, reduced weight loss and retention of fruit firmness for the first six days, all of which improved the commercial value of the fruit. The shelf life of coated fruit was prolonged for 12 days in comparison with the untreated control which ripened within seven days and lost marketability after Day 6. The pilot study demonstrates the effectiveness of a starch-based edible coating formulation for improving the ambient storage capacity of banana fruit.

The aim of this study was to determine the influence of the fillet structure on the deboning force required to remove salmon and trout pin bones. Salmon and trout fillets with differing fillet structure were used, in order to study the importance of the fillet structure on the deboning process. In the first test naturally gaping and non-gaping fillets were compared. To confirm the role that the collagen plays within the fillet structure, the fillets underwent series of treatments. Fillets were put into (i) a collagenase solution to remove the collagen in the fillet and (ii) a calcium chloride solution to determine if collagen was the main influential factor. Both treated salmon and trout fillets were again compared to untreated fillets from the same batch. The results indicate that collagenase and calcium chloride have a large interaction on deboning force compared to water or no treatments.

The study investigated the possibility of enhancing the shelf life of plum fruit coated with rice starch-ι-carrageenan (RS-ι-car) composite coating blended with sucrose fatty acid esters (FAEs). Film solution (starch 3%, carrageenan 1.5% and FAEs 2%) was prepared by mixing the ingredients and properties of stand-alone films (physical, mechanical, barrier and surface morphology) were studied before applying the coating on fruit surface. Fruit were stored at 20 °C for 3 weeks and analyzed for weight loss, ethylene production, respiration rate, color change, firmness, and titratable acidity (TA) and soluble solid content (SSC). Surface morphology of stand-alone film and fruit surface (after applying on the plum fruit) was studied using scanning electron microscopy (SEM). Phytochemical analysis was performed during the storage period and total phenolic content (TPC), total antioxidant capacity (TAC), flavonoid content (FC) and free radical scavenging activity were determined. The rice starch composite coating was shown to be effective in reducing both weight loss (WL) and respiration rate and inhibiting the endogenous ethylene production when compared to the uncoated control fruit stored at room temperature (p

Novel edible composite coatings based on pea starch and guar gum (PSGG), PSGG blended with lipid mixture containing the hydrophobic compounds shellac and oleic acid (PSGG-Sh), and a layer-by-layer (LBL) approach (PSGG as an internal layer and shellac as an external layer), were investigated and compared with a commercial wax (CW) and uncoated fruit on postharvest quality of ‘Valencia’ oranges held for up to four weeks at 20 °C and 5 °C with an additional storage for 7 d at 20 °C. The incorporation of lipid compounds into the PSGG coatings (PSGG-Sh) generally resulted in the best performance in reducing fruit respiration rate, ethylene production, weight and firmness loss, peel pitting, and fruit decay rate of the coated oranges. Fruit coated with PSGG-Sh and a single layer PSGG coatings generally resulted in higher scores for overall flavor and freshness after four weeks at 5 °C followed by one week at 20 °C than uncoated fruit, as assessed by a sensory panel. Although the LBL coating reduced weight loss and respiration rate with improved firmness retention to a greater extent than the single layer PSGG coating, the bilayer coating also resulted in higher levels of ethanol causing increased perception of off-flavors. Overall results suggested that PSGG-based edible coatings could be a beneficial substitute to common commercial waxes for maintaining quality and storability, as well as extending shelf life of citrus fruit and potentially other fresh horticultural produce.

Olive pomace is a waste produced by the olive oil industry in massive quantities each year. Disposal of olive pomace is difficult due to high concentrations of phenolic compounds, which is an environmental concern. However, phenolic compounds have applications in the health industry. Therefore, extraction of phenolic compounds from olive pomace has the potential to remove an environmentally hazardous portion of pomace while creating an additional source of income for farmers and producers. Using advanced technologies including Ultrasound Assisted Extraction (UAE), combined with water as an extraction solvent, has recently gained popularity. The present study outlines the optimal UAE conditions for the extraction of phenolic compounds with high antioxidant activity from olive pomace. Optimal conditions were developed using RSM for parameters power, time and sample-to-solvent ratio. Total phenolic compounds determined by Folin Ciocalteu method and total major bioactive compounds determined by HPLC as well as antioxidant capacity (DPPH and CUPRAC) were investigated. The optimal conditions for the extraction of phenolic compounds with high antioxidant activity were 2 g of dried pomace/100 mL of water at 250 W power for 75 min. UAE improved the extraction efficiency of water and yielded extracts with high levels of phenolic compounds and strong antioxidant activity.

Response surface methodology (RSM) based on a three-factor and three-level Box–Behnken design was employed for optimizing the aqueous ultrasound-assisted extraction (AUAE) conditions, including extraction time (35–45 min), extraction temperature (45–55 °C) and ultrasonic power (150–250 W), for the recovery of total phenolic content (TPC) and rutin from lemon by-products. The independent variables and their values were selected on the basis of preliminary experiments, where the effects of five extraction parameters (particle size, extraction time and temperature, ultrasonic power and sample-to-solvent ratio) on TPC and rutin extraction yields were investigated. The yields of TPC and rutin were studied using a second-order polynomial equation. The optimum AUAE conditions for TPC were extraction time of 45 min, extraction temperature of 50 °C and ultrasonic power of 250 W with a predicted value of 18.10 ± 0.24 mg GAE/g dw, while the optimum AUAE conditions for rutin were extraction time of 35 min, extraction temperature of 48 °C and ultrasonic power of 150W with a predicted value of 3.20 ± 0.12 mg/g dw. The extracts obtained at the optimum AUAE conditions were compared with those obtained by a hot water and an organic solvent conventional extraction in terms of TPC, total flavonoid content (TF) and antioxidant capacity. The extracts obtained by AUAE had the same TPC, TF and ferric reducing antioxidant power as those achieved by organic solvent conventional extraction. However, hot water extraction led to extracts with the highest flavonoid content and antioxidant capacity. Scanning electron microscopy analysis showed that all the extraction methods led to cell damage to varying extents.

Polyphenols of citrus by-products, due to their antioxidant and antimicrobial activities, could be valorized by pharmaceutical and food industries, adding a value to the citrus processing companies. A number of studies have investigated the effect of ultrasound-assisted extraction (UAE) conditions on the recovery of phenolics derived from citrus waste using both organic solvents or mixed aqueous solvent systems. To maximize efficiency, UAE conditions should be tailored to the physical parameters of the solvent(s) employed. The aim of this study was to investigate the effect of four UAE parameters: particle size (1.40–2.80 mm), extraction time (10–60 min), extraction temperature (23–50 °C) and ultrasonic power (150–250 W) on the simultaneous recovery of p-coumaric acid, caffeic acid, chlorogenic acid, and hesperidin from citrus waste using pure water as a solvent. High-performance liquid chromatography (HPLC) was employed for the identification and quantification of the cited compounds. Particle size was determined to be an important parameter affecting compound recovery, with the exception of chlorogenic acid. A particle size of 1.40 mm resulted in the highest recovery of p-coumaric and caffeic acids (0.25 and 0.58 mg/g, respectively), while higher hesperidin yields were achieved from the particle sizes of 2.00 and 1.40 mm (6.44 and 6.27 mg/g, respectively). Extraction temperature significantly affected only the recovery of the flavanone glycoside (P

The effect of two lemon by‐product aqueous extracts at different concentrations (14, 7, 3.5 and 1 mg mL⁻¹) was tested against the in vitro growth of Alternaria alternata. Prior to extraction, one batch of by‐product was dehydrated by freeze‐drying (untreated by‐product), while the other batch was treated by microwave irradiation in conjunction with freeze‐drying (microwave‐treated by‐product). High‐performance liquid chromatography (HPLC) was employed for the identification of individual phenolic compounds with potent antifungal activities. Both lemon by‐product aqueous extracts inhibited the mycelial growth and suppressed the spore germination of the fungus in a concentration‐dependent manner. In general, the extracts obtained from the microwave‐treated lemon by‐product displayed enhanced antifungal activity than those obtained from the untreated one. Scanning electron microscopy (SEM) revealed that both lemon by‐product extracts affected the hyphal morphology of the fungus. The antifungal activity of the extracts was attributed to their phenolic acid and ascorbic acid contents.

This study aimed to investigate the effects of temperature and initial moisture content (M0) on the critical relative humidity (RHc) of whole-grain breakfast wheat biscuit, using the Dynamic Vapor Sorption (DVS) equilibrium and the Differential Scanning Calorimetry (DSC) methods. The effect of glass transition on physical quality of the product, as well as an optimal storage condition were also determined. The findings showed the RHc values of wheat biscuits measured by DVS were close to the relative humidity (RH) of onset glass transition temperature (Tg) measured by DSC. The RHc values indicated positive correlation with M0 and negative correlation with temperature. After the RHc values were defined, wheat biscuits (7% M0) were incubated at the conditions “below” (13.73 ± 0.62% RH), “at” (37.79 ± 0.46% RH) and “above” (54.66 ± 0.68% RH) glass transition area at 20 °C for 15 weeks, during which texture and color of the wheat biscuits were determined. The results showed glass transition affected the biscuits predominantly on crispiness, but the effects were less pronounced on hardness and color. The findings suggested that at 20 °C, wheat biscuits with 7% moisture content are optimally stored at RH below 43.2% (water activity

Green capsicums (Capsicum annum L.) were stored under low pressure (4 kPa) at 10°C for 5 and 11 days with 100% RH. The results showed that the incidence of stem decay under low-pressure storage for 5 and 11 days and storage at ambient atmosphere at 20°C for 3 days was lower compared to fruits that were stored at regular atmosphere at 10°C. Fruit that had been stored at low pressure at 10°C had no symptoms of flesh rots for up to 11 days, whilst fruit which had been stored at regular atmosphere at 10°C had 6% flesh rots after 11 days storage at 10°C.There was no difference in flesh firmness and colour retention between fruits stored at low pressure and regular pressure at 10°C. Capsicums stored at low pressure had higher overall acceptability compared to fruit that were stored at regular atmosphere at 10°C. These results demonstrate the potential of low pressure storage as an effective technique to manage capsicum fruit quality, however, there was no additional benefit when fruits were stored at lo...

Improvements in the hygroscopic properties of starch based films are important to strengthen their mechanical properties. The effects of different hydrophobic components-butyric acid (BA, C4:0), lauric acid (LA, C12:0), palmitic acid (PA, C16:0), oleic acid (OA, C18:1), stearic acid (SA, C18:0) and sucrose fatty acid ester (FAEs) on the rice starch (RS)-ι-carrageenan (ι-car) composite films were investigated. Scanning electron microscopy (SEM), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) in combination with amylose-lipid complexing index (CI) were used to characterise the changes in structure and properties of edible films. The SEM results showed that the surface of films became smoother after the incorporation of fatty acids. Carbon-chain length was a major determinant of CI formation which further influenced the attributes of RS-ι-car films. The addition of FAEs to RS-ι-car improved film thickness, permeability, transparency, tensile properties (TS) and could be used to tailor biodegradable edible films with enhanced properties and future fruit coating applications.

The influence of different plasticizers (glycols, sugars and polyols) on the moisture sorption, mechanical, physical, optical, and microstructure characteristics of pea starch-guar gum (PSGG) film was studied. All plasticizers formed homogeneous, transparent, and smooth films, while PEG-400 did not produce film with suitable characteristics. Fourier transform infrared (FTIR) spectroscopy results indicated some interaction between plasticizers and the polymers. Scanning electron microscopy (SEM) observations of the films presented surfaces without cracks, breaks, or openings which were indicator of the miscibility and compatibility of employed plasticizers with PSGG films. The results showed that the films containing plasticizers with higher functional groups had lower equilibrium moisture content at aw0.4. In general, a reduction in tensile strength and Young's modulus and an increase in elongation at break were detected when molecular weight of plasticizers and relative humidity increased in all film formulations. Films plasticized with monosaccharide showed similar mechanical properties to those with sorbitol, but lower solubility and water vapour permeability (WVP), higher transparency and moisture content than the sorbitol-plasticized films. The most noticeable plasticization effect was exerted by following order: glycerolEGPGxylitolfructosesorbitolmannitolgalactoseglucosesucrosemaltitol.

This study examined the effects of different ratios of shellac (20–60%), stearic acid (SA) (0–2%), and Tween-20 (0.1–0.5 ml) on the water vapor permeability (WVP) and mechanical properties of the pea starch-guar gum (PSGG) films which were evaluated by using response surface methodology (RSM). The incorporation of shellac into the PSGG film structure led to a slightly increased of film thickness. However the addition of higher concentrations of shellac did not improve the moisture barrier of PSGG film owing to the poor distribution of shellac in the film structure. Film formulated with 40% shellac, 1% SA, and 0.3% Tween-20 exhibited optimal functional properties. Moreover, the influence of the incorporation of different emulsifiers into the optimized film matrix was investigated by studying the physical, mechanical, and optical properties of the films. Films containing oleic acid (OA) showed not only lower thickness, WVP, moisture content, and water solubility, but also higher percentage of elongation (E), tensile strength (TS), and transparency compared with other fatty acids tested. Biocomposite pea starch-guar gum-shellac (PSGG-Sh) films containing OA can be considered to be sufficient for most of food packaging applications.

Zucchini (Cucurbita pepo var. cylindrica) were stored at low pressure (4 kPa) at 10°C at 100% relative humidity for 11 days. Fruit quality was examined upon removal and after being transferred to normal atmosphere (101 kPa) at 20°C for three days. Zucchinis stored at low pressure exhibited a 50% reduction in stem-end browning compared with fruit stored at atmospheric pressure (101 kPa) at 10°C. The benefit of low pressure treatment was maintained after the additional three days storage at normal atmospheric pressure at 20°C. Indeed, low pressure treated fruit transferred to regular atmosphere 20°C for three days possessed a significantly lower incidence of postharvest rot compared to fruit stored at regular atmospheric pressure at 10°C. Zucchinis stored at low pressure showed higher levels of acceptability (28% and 36%, respectively) compared to fruit stored at regular atmospheres at 10°C for both assessment times.

Active food packaging based on pea starch and guar gum (PSGG) films containing natural antioxidants (NAs) was developed. Four kinds of NAs (epigallocatechin gallate (EGCG), blueberry ash (BBA) fruit extract, macadamia (MAC) peel extract, and banana (BAN) peel extract) were added into the PSGG-based films as antioxidant additive. The effects of these compounds at different amounts on the physical and antioxidant characteristics of the PSGG film were investigated. The antioxidant activity was calculated with three analytical assays: DPPH radical scavenging ability assay, cupric reducing antioxidant capacity (CUPRAC), and ferric reducing activity power (FRAP). EGCG-PSGG films showed higher antioxidant activity, followed by BBA-PSGG, MAC-PSGG, and BAN-PSGG films, at all concentrations (0.75–3 mg/mL) and with all procedures tested. Additionally, the antioxidant activity of films showed a concentration dependency. The results revealed that addition of NAs made the PSGG film darker and less transparent. However, the moisture barrier was significantly improved when NAs were incorporated into the film. The FTIR spectra were examined to determine the interactions between polymers and NAs. The results suggested that incorporation of EGCG, BBA, MAC, and BAN into PSGG films have great potential for use as active food packaging for food preservation.

Antimicrobial activity of epigallocatechin-3-gallate (EGCG) and two native Australian plants blueberry ash (BBA) fruit and macadamia (MAC) skin extracts against nine pathogenic and spoilage bacteria and seven strains of fungi, using an agar well diffusion assay were investigated. The minimum inhibitory concentrations (MIC) of these compounds were calculated using 96-well microtiter plates method. Finally, active antimicrobial packaging films were prepared by incorporation of EGCG, BBA and MAC extracts at 1-, 2-, 3-, and 4-fold of their correspondence MIC values into edible films based on pea starch and guar gum (PSGG). The antimicrobial activity of films was investigated against target microorganisms by agar disc diffusion technique and quantified using the viable cell count assay. Among the test microorganisms, Salmonella typhimurium and Rhizopus sp. were the most resistance to active films. Films containing EGCG showed the highest activity against all test strains. As the concentration of compounds increased higher than 2 × MIC, the mechanical characteristics of the films were affected considerably. The results indicated that EGCG-PSGG, BBA-PSGG and MAC-PSGG films can be used as active food packaging systems for preserving food safety and prolonging the shelf-life of the packaged food.

Freshly harvested vine-ripened tomatoes (Solanum lycopersicum cv. Neang Pich) were stored at low pressure (4 kPa) at 10°C for 11 days with 100% RH. Fruit quality was examined upon removal and after...

Mature green tomatoes (Solanum lycopersicum L. cv Neang Pich) were exposed to 13.6 kJ m−2 UV-C or 0.5 μL L−1 1-MCP or combination of 13.6 kJ m−2 UV-C and 0.5 μL L−1 1-MCP, with appropriate untreated controls. After treatment, tomatoes were stored in air containing 0.1 μL L−1 ethylene at 20°C and 100% RH. The untreated fruit ripened significantly faster than those of all other treatments. UV-C treatment alone was able to delay fruit ripening by up to 5 days longer compared to untreated fruits whilst the additional of 1-MCP further delayed fruit ripening. UV-C and 1-MCP treatments alone or in combination had significantly slower ethylene production rates throughout the storage period. The fruit treated with the combination of 1-MCP and UV-C was significantly firmer and had higher total phenolic content compared to that of the other treatments. However, there was no difference between treatments in soluble solids content/titratable acids ratio, chlorophyll content, lycopene content and total antioxid...

Summary The aim of this study was to investigate the effect of freeze-drying, hot air-drying and vacuum-drying at 70, 90 and 110 °C, on dried lemon pomace polyphenols and antioxidant capacity. The total phenolic content and antioxidant capacity were higher in lemon pomace dried by hot air or under vacuum than those dried by freeze-drying and increased as the temperature increased. The highest total flavonoid content was recorded in the pomace dried under vacuum at 70 and 90 °C. Lemon pomace dried by freeze-drying had the highest neohesperidin content, whereas pomace dried under vacuum at 70 °C had the highest rutin and p-coumaric acid content. The highest gallic acid content was recorded in the pomace dried by hot air at 110 °C. The results of this study indicate that drying technique should be carefully selected according to the bioactive compounds aimed to be extracted.

The influence of process variables (pea starch, guar gum and glycerol) on the viscosity (V), solubility (SOL), moisture content (MC), transparency (TR), Hunter parameters (L, a, and b), total color difference (ΔE), yellowness index (YI), and whiteness index (WI) of the pea starch based edible films was studied using three factors with three level Box–Behnken response surface design. The individual linear effect of pea starch, guar and glycerol was significant (p 0.93). Three-dimensional response surface plots were established to investigate the relationship between process variables and the responses. The optimized conditions with the goal of maximizing TR and minimizing SOL, YI and MC were 2.5 g pea starch, 25% glycerol and 0.3 g guar gum. Results revealed that pea starch/guar gum edible films with appropriate physical and optical characteristics can be effectively produced and successfully applied in the food packaging industry.

The mechanical properties and moisture sorption at relative humidity (RH) range of 11–94%, water vapor permeability (WVP), solubility in water and color of the pea starch films as a function of glycerol were examined. The results showed that increasing the concentration of plasticizer resulted in improvement of the tensile strength of the films at RH

A large amount of citrus waste is generated annually. This waste is of great economic worth, since it contains high levels of polyphenols, which have attracted scientific interest due to their potent antimicrobial and antiradical activities. Pre-treatment is a crucial step that precedes the extraction process and influences the yields and quality of polyphenols. This review emphasizes the effect of different drying processes, such as freeze drying, hot-air drying, vacuum drying, infrared drying, and high-speed drying, on the polyphenol retention in citrus by-products. Further treatments of the dried citrus by-products for assisting the liberation of bound polyphenols are also provided and comprehensively discussed., Centro de Investigación y Desarrollo en Criotecnología de Alimentos

The green Tahitian limes (Citrus latifolia) were exposed to 7.2 kJ m(−2) UV-C and 0.5 μL L(−1) 1-methylcyclopropene (1-MCP) treatments both separately and in combination. After treatment, fruit were stored in ethylene free (i.e. air containing

The effects of high pressure processing (HPP) on barramundi muscle at 0.1 MPa (control), 150 MPa, 200 MPa, 250 MPa and 300 MPa at 11 ± 2 °C for 3 min were studied before and after immediate blast freezing and storage at −18 °C for up to 18 weeks. Physicochemical measurements including colour, texture profile, drip loss, pH, free fatty acids and thiobarbituric acid (TBA) values were carried out. HPP at 200 MPa significantly increased hardness and delayed lipid oxidation during frozen storage (for up to 18 weeks) without resulting in a cooked appearance of barramundi muscle. However, drip loss of barramundi muscle pressurised at 200 MPa was similar to control samples and during frozen storage. Application of pressures higher than 250 MPa for 3 min resulted in the loss of visual freshness and increased drip loss of barramundi muscle. Thus, application of HPP at an appropriate level (150–200 MPa) before freezing could improve the quality of frozen barramundi muscle.

This study investigated the effects of different storage conditions, temperatures of −20, 10, room temperature (RT), 40 and 63 °C for up to 12 months in the presence or absence of air and light, on the stability of an encapsulated gac ( Momordica cochinchinensis ) oil powder. A stability trial of the encapsulated oil powder incorporated into yoghurt, pasteurised milk and cake mix stored at 4 ± 0.5 °C and RT for different storage times was also carried out. The results showed that a progressive degradation of colour, β-carotene and lycopene, and a progressive increase in surface oil content and peroxide value (PV) occurred in the encapsulated powders with increasing storage temperatures and storage times. However, the degradation was much less when the encapsulated powder was stored at low temperature in the absence of air and light. The degradation of β-carotene and lycopene in all samples during storage fitted a first-order reaction. The sorption curves of the encapsulated powders at 10, 30 and 40 °C were fitted with BET and GAB models. The results also showed that the encapsulated gac oil powder could be successfully incorporated into food products in terms of retention of colour, β-carotene and lycopene, and low PV.

Bitter melon ( Momordica charantia L.) is a medicinal fruit often used for the treatment of diabetes, due to its content of saponins, phenolics and flavonoids and its antioxidant capacity. The aims were to use response surface methodology (RSM) to optimise the inlet (125.6, 130, 140, 150, 154.1 °C) and outlet (72.9, 75, 80, 85, 87.1 °C) temperatures for the spray-drying encapsulation of a bitter melon aqueous extract using a combination of maltodextrin and gum Arabic as encapsulating agent and to determine the stability of the optimised encapsulated powder under various storage conditions. The RSM models were adequate to describe and predict the responses for the process yield, the retentions of saponins, phenolics, flavonoids and antioxidant activity, the moisture content and the water solubility index with an overall R 2 ≥ 0.91. The optimal inlet and outlet temperatures were determined to be 140 °C and 80 °C, respectively. The optimised spray-dried powder had high values for process yield (71.4 ± 1.4%), retention of bioactive compounds and antioxidant activity (≥ 87.9 ± 2.6%), water solubility index (89.9 ± 0.51%) and had a low moisture content (2.2 ± 0.1%), which was below the M o = 5.71 predicted by the BET model. However, in terms of the morphology of the powder particles under scanning electron microscopy and loss of the bioactive compounds and antioxidant activity, the safest range for preserving the powder at 25 °C was determined to range from 22.5% to 33.8%. The encapsulated powder was also slightly more stable at − 20 and 10 °C than at 30 °C, over 150 days. Therefore, it can be concluded that spray-drying with the inlet temperature at 140 °C and the outlet temperature at 80 °C resulted in a very stable encapsulated powder of the bitter melon aqueous extract.

The study aimed to optimise the ultrasound-assisted aqueous extraction of oil, β-carotene and lycopene from powdered microwave-dried gac arils. Ultrasound power, extraction time, powder particle size and the ratio of water to gac powder during the extraction, the centrifugal force used to recover the extracted components were investigated. Microwave-drying followed by aqueous extraction without ultrasound-assistance and air-drying followed by aqueous extraction with or without ultrasound-assistance was also carried out for comparisons. The gac material left behind after the extractions was also investigated using scanning electron microscopy (SEM). The results showed that ultrasound power of 32 W/g of aril powder, extraction time of 20 min, powder particle sizes of 0.3–0.5 mm, a ratio of water to powder of 9 g/g and a centrifugal force of 6,750×g gave optimal extraction efficiencies for oil (90%), β-carotene (84%) and lycopene (83%), and the oil had a low peroxide value (PV) of 2.2 meq/kg. The SEM analysis confirmed that the combination of microwave-drying followed by ultrasound-assisted aqueous extraction caused strong disruption of the gac aril cellular structures, which was consistent with the high extraction of oil, β-carotene and lycopene obtained with the combination. It was concluded that gac oil containing high amounts of β-carotene and lycopene and having a low PV could be extracted using microwave-drying and ultrasound-assisted aqueous extraction.

Olea europaea L. leaves are an agricultural waste product with a high concentration of phenolic compounds, especially oleuropein. Oleuropein has been shown to exhibit anti-proliferative activity against a number of cancer types. However, they have not been tested against pancreatic cancer, the fifth leading cause of cancer related death in Western countries. Therefore, water, 50% ethanol and 50% methanol extracts of Corregiola and Frantoio variety Olea europaea L. leaves were investigated for their total phenolic compounds, total flavonoids and oleuropein content, antioxidant capacity and anti-proliferative activity against MiaPaCa-2 pancreatic cancer cells. The extracts only had slight differences in their phytochemical properties, and at 100 and 200 μg/mL, all decreased the viability of the pancreatic cancer cells relative to controls. At 50 μg/mL, the water extract from the Corregiola leaves exhibited the highest anti-proliferative activity with the effect possibly due to early eluting HPLC peaks. For this reason, olive leaf extracts warrant further investigation into their potential anti-pancreatic cancer benefits.

The aim of this study was to develop an optimal formulation for preparation of edible films from chitosan, pea starch and glycerol using response surface methodology. Three independent variables were assigned comprising chitosan (1-2%), pea starch (0.5-1.5%) and glycerol (0.5-1%) to design an empirical model best fit in physical, mechanical and barrier attributes. Impacts of independent variables on thickness, moisture content, solubility, tensile strength, elastic modulus, elongation at break and water vapor permeability of films were evaluated. All the parameters were found to have significant effects on physical and mechanical properties of film. The optimal formulation for preparation of edible film from chitosan, pea starch and glycerol was 1% chitosan, 1.5% pea starch and 0.5% glycerol. Edible films with good physical and mechanical properties can be prepared with this formulation and thus this formulation can be further applied for testing on coating for fruit and vegetables.

This chapter focuses on the recovery of bioactive compounds, particularly phenolic compounds and dietary fiber, from fruit juice industry solid waste. Extraction, isolation and potential applications of phenolic compounds and dietary fiber recovered from fruit solid waste in the food industry will be discussed. With the continuity of new discoveries on extractions, isolation and characterization techniques, the use of such waste as cheap raw material to produce bioactive compounds on a commercial scale becomes tangible on a large scale. Without any extraction step prior to the fiber preparation, dietary fibers obtained directly from fruit waste contain high amounts of bioactive compounds, such as phenolic compounds, terpenes, carotenoids, depending on the fruit sources. In many reports on the use of bioactive compounds from fruit waste in food products, antioxidant activity is reported to have a synergistic effect with the addition of dietary fiber.

Response surface methodology (RSM) was used to optimise the parameters for phenolic extraction from apple pomace using water, extraction time, extraction temperature and pomace to water ratio. The responses from these parameters were evaluated by measuring the total phenolic content and antioxidant activity of extracts. The optimum extraction parameters found in this study were 30 min extraction time, 85°C extraction temperature and 0.05 pomace to water ratio. A verification experiment of these extraction parameters was performed, along with three other corroborative sets of parameters. There was no significant difference between the predicted and actual values, confirming that the predictions using the models obtained through RSM were valid.

The objective of this study was to optimise the spray drying conditions for the encapsulation of Gac oil using response surface methodology. Results indicated that the corresponding response surface model was sufficient to describe and predict encapsulation efficiencies (EEs) in terms of the oil, β-carotene, lycopene, encapsulation yield (EY), moisture content (MC), water solubility index (WSI) and peroxide value (PV) with R 2 of 0.92, 0.91, 0.89, 0.85, 0.89, 0.98 and 0.97, respectively. Under optimal conditions (inlet and outlet temperatures of 154 and 80 °C), the response variables including the EEs of the oil, β-carotene, lycopene, EY, MC, WSI and PV were predicted and validated as 87.22%, 82.76%, 84.29%, 52.78%, 4.90%, 90.29% and 4.06 meq/kg, respectively. Furthermore, physicochemical, reconstitution and colour properties of the optimally encapsulated powder were also determined. It was concluded that this powder containing high content of unsaturated fatty acids, β-carotene and lycopene, and having the attractive red-yellow colour can be used as nutrient supplement and natural food colourant.

UNLABELLED Bitter melon, Momordica charantia L. (Cucurbitaceae), aqueous extracts are proposed to have health-promoting properties due to their content of saponins and their antioxidant activity. However, the optimal conditions for the aqueous extraction of saponins from bitter melon and the effects of spray drying have not been established. Therefore, this study aimed to optimize the aqueous extraction of the saponins from bitter melon, using response surface methodology, prepare a powder using spray drying, and compare the powder's physical properties, components, and antioxidant capacity with aqueous and ethanol freeze-dried bitter melon powders and a commercial powder. The optimal aqueous extraction conditions were determined to be 40 °C for 15 min and the water-to-sample ratio was chosen to be 20:1 mL/g. For many of its physical properties, components, and antioxidant capacity, the aqueous spray-dried powder was comparable to the aqueous and ethanol freeze-dried bitter melon powders and the commercial powder. The optimal conditions for the aqueous extraction of saponins from bitter melon followed by spray drying gave a high quality powder in terms of saponins and antioxidant activity. PRACTICAL APPLICATION This study highlights that bitter melon is a rich source of saponin compounds and their associated antioxidant activities, which may provide health benefits. The findings of the current study will help with the development of extraction and drying technologies for the preparation of a saponin-enriched powdered extract from bitter melon. The powdered extract may have potential as a nutraceutical supplement or as a value-added ingredient for incorporation into functional foods.

The application of high pressure for processing fish muscles has showed a great potential on improving the physicochemical, microbial and sensory quality of fish muscles. High pressure results in the inactivation of micro-organisms and autolytic enzymes and lead to an extension of fish muscles shelf life. High pressure inhibits the formation of putrefactive compounds and maintains the hardness of fish muscles, resulting in higher sensory quality compared to untreated muscle over storage time. However, the discolouration, cooked appearance and lipid oxidation are the drawbacks that could limit the application of high pressure on fish muscles. Besides, pressure-induced gelling and high-pressure freezing/thawing of fish muscles are the main areas being investigated intensively to obtain the benefits of high-pressure processing on fish muscles.

The objective of this study was to optimize the wall material concentration and the oil load on the encapsulation of Gac oil using spray drying by response surface methodology. Results showed that the quadratic polynomial model was sufficient to describe and predict encapsulation efficiencies in terms of oil, β-carotene, lycopene, peroxide value (PV), moisture content (MC), and total color difference (Δ E) with R 2 values of 0.96, 0.95, 0.86, 0.89, 0.88, and 0.87, respectively. Under optimum conditions (wall concentration of 29.5 % and oil load of 0.2), the encapsulation efficiencies for oil, β-carotene, lycopene, PV, MC, and Δ E were predicted and confirmed as 92 %, 80 %, 74 %, 3.91 meq/kg, 4.14 % and 12.38, respectively. The physical properties of the encapsulated oil powders obtained by different formulations were also determined. It was concluded that the protein-polysaccharide matrix as the wall material was effectively used for spray-drying encapsulation of Gac oil.

Gac fruit (Momordica cochinchinensis Spreng) aril contains high levels of bioactive compounds including β-carotene, lycopene and fatty acids. Therefore, it is important to find an extraction method of Gac oil resulting in the highest content of bioactive compounds. The effects of microwave and air-drying pre-treatments of Gac aril prior to hydraulic pressing and Soxhlet extraction on the oil yield, nutrients and chemical properties of the oil were compared. Results showed that the highest oil yield could be obtained when the aril was microwave-dried before Soxhlet extraction. This finding was explained by microstructural changes of the dried arils. Microwave-drying prior to pressing resulted in the highest content of β-carotene (174 mg/100 mL) and lycopene (511 mg/100 mL) in the oil extract. Oleic acid (48%) and linoleic acid (18%) were found to be the dominant fatty acids in the oil extracts. Gac oil with the lowest acid (0.69 mg KOH/g) and peroxide values (1.80 meq O2/kg) was extracted when microwave-drying was applied prior to pressing. It can be concluded that the microwave drying pre-treatment before pressing was better than the air-drying pre-treatment for extracting Gac oil of high quality.