Zein-based anti-browning cling wraps for fresh-cut apple slices

The usage of cling wraps is emerging as an easy and cost-effective approach to protect fresh-cut fruits and vegetables from dust, whilst improving visual appeal on retail counters. This study focused on developing an alternate, protein-based packaging material as a food grade cling wrap for food packaging applications. Zein-based cling wraps were produced, and their physical and mechanical characteristics were evaluated and compared with conventionally used chitosan biopolymer films and commercial synthetic polymer films. Antioxidant potential of the prepared films was studied, and the effectiveness of the developed films as anti-browning cling wraps was evaluated using studies conducted on fresh-cut apple slices at ambient conditions. Anti-browning effects were in par with polymeric counterparts; however, zein cling wraps could better prevent weight loss in apple slices. Zein-based films can be adopted as biodegradable food grade cling wraps as an alternative to chitosan and synthetic polymeric materials.     

Determination and Health Implication of the Erucic Acid Content of Broccoli Florets, Sprouts, and Seeds

The erucic acid content of broccoli florets, sprouts, and seeds was found to be about 0.8, 320, and 12100 mg/100 g, respectively. Using the erucic acid limit established for canola oil in the U.S.A. and Canada as a guideline, the estimated dietary intake of erucic acid from florets and sprouts was considered of little consequence, whereas in seeds a relatively small amount (about 35 g/wk) equaled our calculated exposure limit for erucic acid. Additionally, the most complete fatty acid distribution yet published for the various forms of broccoli are presented.     

Effect of Calcium Lactate, 4-Hexyl Resorcinol and Vacuum Packing on Physico-chemical, Sensory and Microbiological Qualities of Minimally Processed Litchi (Litchi chinensis Sonn.)

Litchi (Litchi chinensis Sonn.) fruits are very susceptible to pericarp browning which adversely affects consumer acceptability even though the aril portion remains in excellent condition. Litchi arils (litchis) were treated with a solution containing 0–2% (w/v) calcium lactate (CL), 0–0.02% (w/v) 4‐hexyl resorcinol (4‐HR) and 1% potassium sorbate. The pH of solution was adjusted to 4.0 with citric acid. Treated litchis were packed in polystyrene trays, over‐wrapped with polypropylene film, vacuum‐packed (0, 47409.3, 94831.9 Pa) and stored at 4 ± 2 °C. Drip losses, pH, total soluble solids (TSS), sensory attributes and microbiological quality of stored samples were estimated. A four‐factor, three‐level experimental design (D₆ Hokes design) with 19 experiments was chosen. Mathematical models were developed to analyse and predict the effect of CL, 4‐HR, in‐package vacuum and storage time on the responses. TSS, pH and sensory scores decreased significantly (P 0.01), whereas drip losses and microbial count increased significantly (P 0.01) with time. Drip loss was significantly (P 0.1) reduced by addition of CL. 4‐HR prevented browning and changes in colour score during storage were significantly less. Vacuum in packages exerted significant (P 0.01) effect over pH, TSS, sensory and microbiological qualities of minimally processed litchis.     

迭香精油活性贴对鲜切猪肉保鲜效果的研究

目的 为了提高迷迭香精油(REO)的稳定性,开发出一种安全、便捷的实用型活性包装。方法 以迷迭香精油为活性成分,采用三步法(乳化、包埋、多层复合)制备出精油缓释活性贴,并验证其对鲜切猪肉的保鲜效果。结果 在4 ℃下,不同比例的迷迭香精油活性贴均可在一定程度上抑制鲜切猪肉的腐败变质,最佳处理效果的体积比为4∶6,贮藏至第6天时,猪肉的pH值、挥发性盐基氮(TVB–N)含量、硫代巴比妥酸(TBARS)值较空白对照(CK)分别降低了0.7 mg/g、0.073 1 mg/g、0.63 mg/kg;延缓了猪肉色度、汁液流失率、菌落总数(TVC)、感官品质的变化,可延长鲜切猪肉货架期2 d左右。结论 制备的缓释型活性贴具有稳定性好、操作简单易行的优势。作为绿色、可生物降解的包装材料,在食品保鲜领域具有潜在的应用价值。     

超高氧高阻隔膜气调包装对鲜切胡萝卜品质的影响

高氧气调包装是近年来研究较多的气调包装方式之一.研究了在不同储藏温度（4,15,25℃）下,高阻隔膜超高氧气调包装的鲜切胡萝卜品质变化规律（对照空气包装）.结果表明,超高氧气调包装显著增加了鲜切胡萝卜的失重率、呼吸强度,同时加速了维生素C、总胡萝卜素含量的损失,但能提高多酚类物质含量.总之,高阻隔膜超氧气调包装不能有效地维持鲜切胡萝卜的品质.     

Broccoli leaf powder as an attractive by-product ingredient: effect on batter behaviour,technological properties and sensory quality of gluten-free mini sponge cake

Broccoli by-products, in particular leaves, are rich sources of nutritional and bioactive components thus could constitute a valuable food additive. Although an upsurge in quantity of gluten-free products is observed further studies are required on improvement of their nutritional quality and palatability. This study aimed to investigate the influence of broccoli leaf powder (BLP) on dough behaviour, and technological characteristics and sensory quality of gluten-free mini sponge cake (GFS). Broccoli leaf powder replaced an equivalent amount (2.5%, 5%, 7.5%; w/w) of corn and potato starches in GFS formulation. Applied BLP increased the instrumental firmness of GFS but sensorial attributes (elasticity, crustiness, mastication and adhesiveness) were similar to the control. All broccoli GFS were vividly green, had small size pores properly distributed. Among them, sample with 2.5% BLP was distinguished for its desirable sensory quality, despite a slightly perceived cabbage aroma and taste. Moderate amount of BLP allows to preserve a good quality GFS improving its attractiveness and palatability.     

Efficacy of thyme oil-alginate-based coating in reducing foodborne pathogens on fresh-cut apples

In this study, the inhibition of an alginate-based edible coating (EC) containing thyme oil (0.05%, 0.35% and 0.65%) was evaluated against Listeria monocytogenes, Salmonella Typhimurium, Staphylococcus aureus and Escherichia coli O157:H7 inoculated onto fresh-cut apples. To investigate the antibacterial mechanism of thyme oil, the constituent compounds of that were analysed by gas chromatography-mass spectrometry (GC-MS), and the cellular damage of pathogens was observed by scanning electron microscopy (SEM). Results showed that alginate-based EC containing thyme oil effectively inhibited the growth of pathogens on fresh-cut apples. GC-MS analysis revealed thymol (47.23%) as the major compounds in thyme oil. SEM showed that the cell membrane of foodborne pathogens was damaged by thyme oil, causing their inactivation. Treatment with alginate-based EC containing 0.05% thyme oil preserved the sensory characteristics of fresh-cut apples. Therefore, using alginate-based EC with thyme oil may represent a potential approach to preserve and enhance the safety of fresh-cut apples.