Quality and antioxidant capacity of fresh‐cut apple wedges enriched with honey by vacuum impregnation

The effect of vacuum impregnation (VI) of fresh‐cut apple wedges with honey, in presence and absence of a browning inhibitor on physicochemical, sensory and antioxidant properties over 7 days of storage at 2–4 °C was studied. Infusion of wedges with honey resulted in very little weight change indicating loss of internal water and ingress of honey carbohydrates into the wedges, hence the correlation coefficients with soluble solids content (r = ?0.91) and dry matter (r = ?0.77). Water infused samples showed the highest water uptake resulting in an increase in weight of 30%. Browning (P < 0.001) and firmness (P < 0.001) of apple wedges were the quality parameters most affected by VI. Samples dipped in browning inhibitor prior AS1 showed slightly better performance than undipped wedges with regard to browning and firmness. Total phenol content and antioxidant activity were significantly (P < 0.001) lower for honey infused apple wedges.     

Effects of sprayer configuration on efficacy for the control of scab on crabapple using electron beam analysis

Foliar diseases like apple scab result in significant economic losses to growers each year. Assessment in past studies involved only macroscopic disease ratings. More complete knowledge of the fate and behavior of fungicide has been needed to reduce pesticide use with less off‐target contamination. Field studies were conducted in a production nursery for over 4 years. A moderately susceptible cultivar of ornamental crabapple, Malus spp. cv “Candied Apple”, was sprayed with a fungicide using two sprayer/nozzle configurations. The fungicide used in this study was Mankocide, combination of Cu(OH)₂ and mancozeb that permitted electron beam analysis (EBA) identification based on the presence of Cu, MN and Zn in the molecule and formulation. EBA was conducted using a cold field emission scanning electron microscopy and energy dispersive x‐ray microanalyzer. Fresh leaf samples were placed on sticky stubs after each fungicide treatment. The presence or absence of fungal conidia and fungicide residue were measured. EBA permitted direct visualization and identification of the pathogens, morphologically, and chemical characterization of fungicide present. EBA was useful to quantify disease control related to fungicide coverage, sprayer configuration and treatment efficacy. SCANNING 31: 24–27, 2009. Published 2009 by Wiley Periodicals, Inc.     

The effects of oils and frying temperatures on the texture and fat content of potato crisps

The purpose of the study was to determine the effects of oils and frying temperatures on fat content and texture of potato crisps.     

Antioxidative and anti-hydrogen peroxide activities of various herbal teas

Herbal teas, i.e., extracts of herbs, are popular because of their fragrance and antioxidative activity. Since the antioxidative activity comes mainly from polyphenols, total polyphenol concentrations and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging activities in herbal teas were measured and compared. Levels of H₂O₂ in the teas were also examined, since the production of H₂O₂ in beverages such as coffee and green tea, has been reported. Only a small amount of H₂O₂ was detected in the herbal teas just after their preparation with hot water. However, H₂O₂ was gradually produced during incubation at 25 °C after extraction with hot water, especially when the teas were incubated in phosphate buffer at pH 7.4. To examine the anti-H₂O₂ activity of herbal teas, various teas were added to a catechin-enriched green tea, which produce much H₂O₂, and they were incubated at 25 °C for one day. Addition of hibiscus and thorn apple tea decreased the production of H₂O₂ in the catechin-enriched green tea, possibly because of a lowering of the pH of the mixture.     

Plant Volatiles Mediate Host-Finding Behavior of the Apple Leafcurling Midge

The behavioral responses of apple leafcurling midge,Dasineura mali Kieffer, mated females to foliage from host and nonhost trees were investigated in a wind tunnel. When released downwind of apple or pear foliage, females exposed to apple were more likely to exhibit upwind flight and to approach and land on foliage. On apple foliage, landings were concentrated on buds and immature leaves. Probability of taking flight and latency to flight did not differ for females exposed to apple and pear. When foliage was placed behind screens to obscure plant visual stimuli, females again distinguished between apple and pear, with more of the females exposed to apple odors flying upwind and landing. Females exposed to pear odors were more likely to fly upwind, approach, and land than females exposed to clean air. Odors from immature apple foliage triggered orientation responses in a larger percentage of females than odors from mature apple foliage. A dichloromethane extract of immature apple foliage also triggered orientation responses.     

Isolation and Identification of Female Sex Pheromone and Development of a Sex Attractant for Lacanobia subjuncta

Extracts of terminal abdominal segments of female Lacanobia subjuncta contained (Z)-11-hexadecenyl acetate, (Z)-11-hexadecenal, and (Z)-11-hexadecenol at a ratio of 1:0.2:0.02. (Z)-11-hexadecenyl acetate and (Z)-11-hexadecenal were most effective as a lure for trapping males when loaded in rubber septa at ratios near 3:1, respectively. The complete three-component blend was most effective as a lure for trapping males when loaded in rubber septa at a ratio of 3:1:0.08 for the acetate, aldehyde, and alcohol, respectively. In a comparison of doses of this three-component blend, greatest numbers of males were captured with 6.1 mg per rubber septum. These components, when loaded with an optimum ratio of components and suitable dose, should provide a useful lure for trapping Lacanobia subjuncta in agroeco-systems, permitting monitoring of distribution, emergence, and flight periods.     

低醇苹果汁饮料发酵工艺的优化

以苹果为原料,利用高效活性酿酒干酵母发酵制得苹果汁.通过对产品的工艺条件进行试验,确定出最佳工艺条件为:接种量5%、发酵时间60h、质量比50%,在酿酒活性干酵母茵的最适发酵温度33℃下发酵培养,并通过试验分析方法的选择进行调配.此低醇苹果汁饮料产品感官指标上佳,口味独特,产品外观为诱人的浅黄色或金黄色.     

Modelling the respiration rate of fresh-cut Annurca apples to develop modified atmosphere packaging

In this work, the effect of temperature, oxygen, red coloration process and post-harvest storage time on the respiration rate of fresh-cut Annurca apples was studied to properly develop modified atmosphere packaging. Our results showed that the red coloration process and the post-harvest storage time did not affect the respiration rate or the respiratory quotient of fresh-cut Annurca apples in the range of temperature studied (5–20 °C). A Michaelis–Menten-type equation, with the model constants described by means of an Arrhenius-type relationship, was used for predicting respiration rate on varying the temperature and O₂ concentration in the head space. The maximal respiration rate (mL kg h⁻¹) (RR_max) and the O₂% corresponding to     values estimated at the reference temperature (12.5 °C), i.e. the average of the experimental temperature ranges, were, respectively, 6.77 ± 0.1 mL kg⁻¹ h⁻¹ and 0.68 ± 0.07% v/v, and the activation energy of the aerobic respiration rate of fresh-cut Annurca apples was estimated at 51 ± 1 kJ mol⁻¹. The model works well to develop a modified atmosphere for fresh-cut Annurca apples.     

Efficacy of sodium chlorite as an inhibitor of enzymatic browning in apple slices

Sodium chlorite (SC) is an effective sanitizer for inhibiting microbial growth. This investigation was conducted to determine the efficacy of SC as a browning control agent for use on fresh-cut apple slices, applied alone, or in conjunction with organic acids. Additionally, the authors compared the efficacy of SC to that of acidified sodium chlorite (ASC) and to several other salts and examined the effect of pH and several different organic acids on efficacy of SC. The fresh-cut apple slices were dipped in treatment solutions for 1 min, then drained and placed in plastic containers at 20 °C for 24 h, and finally stored in polyethylene bags at 5 °C for 2 weeks. Color was measured periodically during storage. Lightness (L) values for all treated and control samples measured at 4 h, 24 h, and 2 weeks of storage were compared to L value for untreated samples measured immediately after cutting. Percent decrease in L-values was calculated for each sample at each time interval. Apple slices treated in ASC or SC solution had a significantly smaller decrease in L value indicating less browning than those treated in citric acid or water control at 4 h (P < 0.01), and with the exception of 1 g L⁻¹ ASC and 0.1 g L⁻¹ SC, all other ASC and SC treated slices still had significantly less browning than those for the water control (P < 0.01) at 24 h. After 2 weeks of storage, only SC (0.5–1.0 g L⁻¹), sodium bisulfite (0.5 g L⁻¹) and calcium l-ascorbate (10 g L⁻¹) continued to inhibit browning. Treatment with 0.5 g L⁻¹ SC and pH adjusted in the range from 3.9 to 6.2 using citric acid (CA) reduced browning more effectively than 0.5 g L⁻¹ SC without pH adjustment. Two organic acids, salicylic acid and cinnamic acid, when added to SC solution, were found to achieve even better inhibition of browning than CA at the same pH value.