豆豉纤溶酶液体发酵生产条件的研究

研究了芽孢杆菌菌株WMIl发酵生产豆豉纤溶酶的条件．结果表明,最佳发酵条件为：氮源w（带鱼蛋白胨）=3％,w（酵母膏）=0．5％;碳源w（水溶性淀粉）=3％;无机盐的用量为w（K2HPO4）=0．6％,w（KH2PO4）=0．1％,w（MgSO4）=0．1％,w（CaCl2）=0．04％,c（MnCl2）=10^-4mol／L;w（青霉素）=0．01％;培养基pH=6．0,培养温度为37℃．在此条件下,纤溶酶活性可达2345IU／mL．     

从宫崎县沿岸日向滩海域分离烧酒用酵母及其特性

从宫崎县沿岸日向滩海域分离到烧酒用酵母547株，以烧酒用协会2号酵母等为对照，培养和分离有用菌株。（1）YM培养基：葡萄糖1％，蛋白胨0．5％，酵母膏0．3％，麦芽提取物0．3％，用蒸馏水溶解。（2）分离培养基：用过滤后的海水调制添加了氯霉素（最终浓度0．01g／L-0.1g／L）和丙酸钠最终浓度2％（w／v）的YM培养基。     

大蒜油微囊制备工艺的实验研究

本文报导，以鲜大蒜为原料，经水蒸汽蒸馏而得0．30（w／w）的大蒜油为心材，以明胶─阿拉伯胶为壁材，以37％的甲醛溶液为固化剂，采用复凝聚法制备大蒜油微囊的工艺程序，并研究了大蒜油微囊的质量检测方法，测出微囊的含油率为18．5％（w／w），收得率为82．64％及溶出速度为0．003～0．0016ml／min等主要技术数据。     

松香胺作功能单体阳离子无皂苯丙乳液表面施胶剂的研究

以丙烯腈改性淀粉作分散剂,苯乙烯（St）为硬单体,丙烯酸丁酯（BA）为软单体,松香胺（RA）为功能单体,甲基丙烯酸二甲基氨基乙酯（DM）为阳离子单体,丙烯酰胺（AM）为交联单体,过硫酸钾（K2S2O6）为引发剂,采用无皂乳液聚合技术合成了一种阳离子苯丙乳液表面施胶剂,并对施胶纸张各种性能做了测试。最佳合成工艺是：m（St）／m（BA）=2．5,w（RA）=0．5％,w（DM）=0．9％,w（AM）=0．4％,w（K2S2O8）=0．5％,m（单体）／m（淀粉）=2。     

嗜酸乳杆菌高密度培养及发酵剂的研究

研究了嗜酸乳杆菌的高密度培养条件,并使用喷雾干燥法对嗜酸乳杆菌粉末发酵剂进行了制备。实验表明,嗜酸乳杆菌6012的最佳增菌培养基为：乳清培养基＋0．6％（w／v）低聚异麦芽糖＋0．6％（w／v）黄豆粉＋10％（v／v）胡萝卜汁＋0．5％（w／v）CaCO3,在培养过程中伤脑筋20％柠檬酸钠调节培养基pH值为6．2,37℃静置培养18h,活菌数可达1．0×10^9 cfu/mL。以0．5％甘油＋0．5％葡萄精＋3％大豆分离蛋白＋2％海藻酸钠作为抗热保护剂,菌体经过喷雾干燥,其发酵剂活菌数为8．0×10^9 cfu／g。     

用麦糟生产L-乳酸

研究采用固定化乳酸菌作用麦糟生产L-乳酸，使用一个5升蒸汽喷发反应器，通过蒸汽喷发处理使麦糟液化来获取糖浆。当1kg湿麦糟在30kg／cm^2压力下处理1分钟可从液化麦糟获得60g总糖，而且当液化麦糟添加糖化酶、纤维素酶和半纤维素酶时可生成1．3％（w／v）葡萄糖、0．4％（w／v）木糖和0．1％（w／v）阿拉伯糖。使用鼠李糖乳杆菌NBRC14710从添加吐温80的液化麦糟生产L-乳酸。     

液体深层发酵法生产L-苹果酸的研究

以延胡索酸为原料，经^60Co诱变后获得优良菌株温特曲霉Aspergillus wentti F-891，在1000L罐中液体深层发酵生产L-苹果酸。试验研究了发酵过程中通气量、温度、pH值以及搅拌转速等因素对延胡索酸转化率、L-苹果酸产率的影响。结果表明，液体深层发酵生产L-苹果酸的最佳发酵工艺条件为：延胡索酸浓度11％，通气量1：0．8v／v／min（48h前）～1：1．20v／v／min（48h后），温度30℃（48h前）～25℃（48h后），初始pH值6．0-6．2，发酵周期96h-108h，搅拌转速200r／min；延胡索酸平均转化率83．07％，平均产L-苹果酸108．72g／L。     

微生物催化制备功能性油脂——共轭亚油酸的研究

从酸菜中分离出的一株植物乳杆菌Lactobacillus plantarum诱导培养，在氮气保护下利用休止细胞催化制备共轭亚油酸。0．1M磷酸钠缓冲液、pH值7．0、亚油酸浓度2％（w／v）、细胞浓度20％（w／v）、30℃。反应64h，共轭亚油酸产量最高。c9，t11／t9，c11—CLA异构体在产物脂肪酸中的比例为30％。     

新型大米发酵饮料的研制

以大米为主要原料,经蒸煮糊化、接种根霉、糖化、稀释、加入牛奶,以嗜热链球菌和保加利亚乳杆菌的混合菌剂进行乳酸发酵,再加苹果汁、糖、酸等调配成饮料。通过正交试验得出其最佳工艺参数为：根霉菌剂接种量4％（v／w）,大米糖化醪加纯净水稀释1．5倍,添加鲜牛奶40％（v／v）,接种乳酸菌混合菌剂5％（v／v）,42℃-44℃发酵14h;添加苹果汁15％（v／v）,白砂糖5％（w／v）,柠檬酸0．125％（w／v）,复配稳定剂0．15％（w／v）,用高速剪切混合乳化机5000r／min乳化10min,成品经115℃灭菌15min,符合相应产品的国家食品卫生质量要求。     

高酸值米糠油萃取脱酸工艺的研究

对高酸值米糠油的溶剂萃取脱酸工艺进行了研究。在以95％乙醇为溶剂、萃取温度30℃、油和溶剂比为1：1．8（w／w）的条件下萃取3次，可将米糠油酸值从31．02（KOH）／（mg／g）降至4．52（KOH）／（mg／g），通过碱炼可进一步降低酸值至0．23（KOH）／（mg／g）。该工艺可大幅降低脱酸过程中的炼耗，经蒸发脱溶后可直接获得副产品脂肪酸。     

Direct Use of Apple Pomace in Bakery Products

DRUM-DRIED APPLE POMACE (DDAP), an edible by-product from single pass metallic membrane ultrafiltration of apple puree, was examined for composition and utilization as a source of sugar and dietary fiber in bakery products. Total dietary fiber (TDF) of freezc-dricd apple pomace (FDAP) and DDAP was 35.29% and 33.24%, respectively. Total sugar of the apple pomace concentrate (APC), FDAP, and DDAP was 54.34, 46.26, and 36.71%, respectively. Sensory evaluation demonstrated that the experimental muffins with 50% (w/w) of the plain wheat bran substituted by powdered apple pomace were significantly (p < 0.01) more desirable than the control bran muffins. In addition, experimental moon cookies with flaked apple pomace substituted for 40% (w/w) of the all-purpose flour in the crust and 40% (w/w) of the quick-cooking oats in the filling were significantly (p < 0.01) more desirable than the control moon cookies.     

Effect of ascorbic acid on the odours of cloudy apple juice

Ascorbic acid is used in apple juice as an antibrowning agent. This study investigated the effect of ascorbic acid (0.0–0.2% w/v) on the odours of cloudy apple juice using sensory evaluation and gas chromatography (GC). The increase in ascorbic acid concentration in the apple juice resulted in increases in green and unnatural odours and decreases in fresh, fruity and apple-like odours. In the GC determination, 23 volatile compounds were detected in apple juice. Aroma value, which showed the relative importance of volatile compounds, was used to elucidate the changes in odours of apple juice due to the addition of ascorbic acid. The aroma values of hexanal and trans-2-hexenal in the apple juice with 0.2% w/v ascorbic acid increased about 4 and 5-fold from those in the ascorbic acid-free apple juice, respectively. On the other hand, the aroma values of esters insignificantly changed in the apple juice with ascorbic acid. The increases in aroma values of aldehydes corresponded well with the increase in green odour in the apple juice with ascorbic acid.     

Quality changes in fresh-cut Fuji apple as affected by ripeness stage, antibrowning agents, and storage atmosphere

ABSTRACT:  The effect of ripening state, modified atmosphere, and the use of antibrowning agents was investigated in an attempt to determine optimum ripeness and processing conditions for extending the shelf-life of fresh-cut Fuji apple. Apples were classified in 3 groups: mature-green, partially ripe, and ripe; after peeling and slicing, fruits were treated with 1% (w/v) N -acetylcysteine, or 1% (w/v) ascorbic acid (control), and then packed into polypropylene trays with air or a gas mixture (2.5% O₂+ 7% CO₂+ 90.5% N₂) and sealed. Trays containing the apple slices were stored in darkness at 4 °C ± 1 °C and analyzed periodically during 43 d. Changes in atmosphere composition, color, and firmness were examined. Partially ripe apples, based on their lower ethanol production and maintenance of their original color and firmness, were the most suitable to prepare the fresh-cut commodities. A postcutting dip in 1% (w/v) N -acetylcysteine was the most effective treatment to prevent cut surface browning and preserve the initial appearance of Fuji apple slices during more than 1 mo at 4 °C. Low O₂ and elevated CO₂ (2.5% O₂+ 7% CO₂) atmosphere extended the shelf life of apple slices because of a significant inhibition of ethylene production.     

Physical and antibacterial properties of edible films formulated with apple skin polyphenols

Fruit and vegetable skins have polyphenolic compounds, terpenes, and phenols with antimicrobial and antioxidant activity. These flavoring plant essential oil components are generally regarded as safe. Edible films made from fruits or vegetables containing apple skin polyphenols have the potential to be used commercially to protect food against contamination by pathogenic bacteria. The main objective of this study was to evaluate physical properties as well as antimicrobial activities against Listeria monocytogenes, Escherichia coli O157:H7, and Salmonella enterica of apple skin polyphenols at 0% to 10% (w/w) concentrations in apple puree film-forming solutions formulated into edible films. Commercial apple skin polyphenol powder had a water activity of 0.44 and high total soluble phenolic compounds and antioxidant capacity (995.3 mg chlorogenic acid/100 g and 14.4 mg Trolox/g, respectively). Antimicrobial activities of edible film containing apple skin polyphenols were determined by the overlay method. Apple edible film with apple skin polyphenols was highly effective against L. monocytogenes. The minimum concentration need to inactive L. monocytogenes was 1.5%. However, apple skin polyphenols did not show any antimicrobial effect against E. coli O157:H7 and S. enterica even at 10% level. The presence of apple skin polyphenols reduced water vapor permeability of films. Apple skin polyphenols increased elongation of films and darkened the color of films. The results of the present study show that apple skin polyphenols can be used to prepare apple-based antimicrobial edible films with good physical properties for food applications by direct contact.     

苹果皮膳食纤维饮料的研制

以苹果皮为原料进行苹果皮膳食纤维饮料的研制,通过正交试验和单因子试验,对饮料中苹果皮、柠檬酸、稳定剂、抗氧化剂、葡萄糖的用量进行探讨,得到苹果皮膳食纤维饮料的最佳工艺配方为：苹果皮25%（w/v）、VC0.014%（w/v）、葡萄糖10%（w/v）、柠檬酸0.015%（w/v）,同时还探讨了苹果皮膳食纤维饮料的稳定性以及色、香、味的保持与稳定。     

Moisture sorption characteristics and glass transition temperature of apple puree powder

The aim of this study was to characterise the influence of different foam‐mat‐drying methods on the moisture sorption characteristics and glass transition temperatures of apple puree powder. Apple puree was foamed with the addition of 2.5% egg albumin and 0.5% methylcellulose. Convective air‐drying and microwave‐drying techniques were used. Also foamed puree with and without maltodextrin (6% or 15% w/w) was freeze‐dried. Moisture equilibrium data of powders were determined by using a static desiccator method in a water activity range of 0.0–0.903. Modulated differential scanning calorimetry (MDSC) was used to obtain the glass transition temperature. No effect of drying method on sorption properties and glass transition temperatures of apple puree powders was observed. The addition of maltodextrin to the apple puree caused an increase in T_g by 10–30 °C depending on the amount of incorporated additive. Addition of maltodextrin significantly reduced the hygroscopicity of apple puree powders.     

Characterization of Osmotolerant Yeasts and Yeast‐Like Molds from Apple Orchards and Apple Juice Processing Plants in China and Investigation of Their Spoilage Potential

Yeasts and yeast‐like fungal isolates were recovered from apple orchards and apple juice processing plants located in the Shaanxi province of China. The strains were evaluated for osmotolerance by growing them in 50% (w/v) glucose. Of the strains tested, 66 were positive for osmotolerance and were subsequently identified by 26S or 5.8S‐ITS ribosomal RNA (rRNA) gene sequencing. Physiological tests and RAPD‐PCR analysis were performed to reveal the polymorphism of isolates belonging to the same species. Further, the spoilage potential of the 66 isolates was determining by evaluating their growth in 50% to 70% (w/v) glucose and measuring gas generation in 50% (w/v) glucose. Thirteen osmotolerant isolates representing 9 species were obtained from 10 apple orchards and 53 target isolates representing 19 species were recovered from 2 apple juice processing plants. In total, members of 14 genera and 23 species of osmotolerant isolates including yeast‐like molds were recovered from all sources. The commonly recovered osmotolerant isolates belonged to Kluyveromyces marxianus, Hanseniaspora uvarum, Saccharomyces cerevisiae, Zygosaccharomyces rouxii, Candida tropicalis, and Pichia kudriavzevii. The polymorphism of isolates belonging to the same species was limited to 1 to 3 biotypes. The majority of species were capable of growing within a range of glucose concentration, similar to sugar concentrations found in apple juice products with a lag phase from 96 to 192 h. Overall, Z. rouxii was particularly the most tolerant to high glucose concentration with the shortest lag phase of 48 h in 70% (w/v) glucose and the fastest gas generation rate in 50% (w/v) glucose.     

Alginate- and gellan-based edible films for probiotic coatings on fresh-cut fruits

ABSTRACT:  Alginate- (2% w/v) or gellan-based (0.5%) edible films, containing glycerol (0.6% to 2.0%), N-acetylcysteine (1%), and/or ascorbic acid (1%) and citric acid (1%), were formulated and used to coat fresh-cut apple and papaya cylinders. Water vapor permeability (WVP) was significantly higher ( P < 0.05) in alginate films (0.30 to 0.31 × 10⁻⁹g m/Pa s m²) than in the gellan ones (0.26 to 0.27 × 10⁻⁹g m/Pa s m²). Addition of 0.025% (w/v) sunflower oil decreased WVP of gellan films (0.20 to 0.22 × 10⁻⁹ g m/Pa s m²). Water solubility of gellan and alginate films at 25 °C (0.47 to 0.59 and 0.74 to 0.79, respectively) and their swelling ratios (2.3 to 2.6 and 1.6 to 2.0, respectively) indicate their potential for coating high moisture fresh-cut fruits. Fresh-cut apple and papaya cylinders were successfully coated with 2% (w/v) alginate or gellan film-forming solutions containing viable bifidobacteria. WVP in alginate (6.31 and 5.52 × 10⁻⁹g m/Pa s m²) or gellan (3.65 and 4.89 × 10⁻⁹ g m/Pa s m²) probiotic coatings of papaya and apple, respectively, were higher than in the corresponding cast films. The gellan coatings and films exhibited better water vapor properties in comparison with the alginate coatings. Values > 10⁶ CFU/g B. lactis Bb -12 were maintained for 10 d during refrigerated storage of fresh-cut fruits, demonstrating the feasibility of alginate- and gellan-based edible coatings to carry and support viable probiotics on fresh-cut fruit.     

BAKING AND SENSORY CHARACTERISTICS OF MUFFINS INCORPORATED WITH APPLE SKIN POWDER

ABSTRACT

Apple fruit skin, a rich source of dietary fiber and phenolics, is a by‐product of apple processing. The feasibility of incorporating dried apple skin powder (ASP) as a value‐added food ingredient in bakery food products using a model system of muffins was investigated. The blanched, dehydrated and ground ASP was incorporated into muffins at 0, 4, 8, 16, 24 or 32% (w/w) levels with replacement of equivalent amount of wheat flour of a standard muffin mixture. The highest level of replacement (32% w/w) had a significant adverse effect on the baking characteristics. A taste panel of 66 panelists showed that the replacement of wheat flour with 8, 16 or 24% ASP in the muffin mixture did not affect the overall acceptability.

PRACTICAL APPLICATIONS

Identification of ways to incorporate apple skins, one of the by‐products of apple pie and sauce manufacturing, as a health food ingredient in human diet could provide many health benefits. Furthermore, better use of the by‐product will also provide benefits to the apple industry as well as solutions for environment concerns associated with disposal. The results of the present study indicate that blanched and dehydrated apple skin powder (ASP) could be considered as an alternative dietary fiber source or specialty food ingredient for muffins. Therefore, the potential for the industrial exploitation of ASP as a health food ingredient for the bakery industry and selected functional foods is promising.     

Pectin from low quality ‘Golden Delicious’ apples: Composition and gelling capability

Pectin was acid-extracted from low quality ‘Golden Delicious’ apple fruit, yielding 16% (w pectin/w apple fruit). Composition and some of its physicochemical and functional properties were assessed. The pectin fraction presented a galacturonic acid content of 65% (w/w), an esterification degree of 57%, an intrinsic viscosity, [η], of 307 ml/g and a molecular weight (Mw) of 112 kDa. Pectin gels were obtained in 60% (w/v) fructose and pH 2.7. Pectin gels at 2.0% and 3.0% (w/v) presented hardness values of 10.2 and 20.4 g after 12 h at 4 °C. The gel hardness was greatly affected by aging (20% and 25% decrease in 48 h for gels at 2% and 3%, respectively). The results attained suggest the use of this gum as a potential texturing agent for the food industry.