解读毕加索“薯片”的女人

17岁的吉纳维夫·拉伯特作为校杂志记者采访毕加索，坦言不理解他的画，他被大大激怒：“难道你们理解薯片的语言吗？”应答可堪经典，机智。

Comparison of the Effects of H_2O_2 and Salicylic Acid on Alternative Respiratory Pathway in Aged Potato Tuber Slices

The influences of exogenous H 2O 2 and salicylic acid (SA) treatments on the alternative respiratory pathway (ARP) in aged potato (Solanum tuberosum L.) tuber slices were compared. The results showed that both H 2O 2(5.0 mmol/L) and SA (0.1 mmol/L) treatments had a significant inducing effect on ARP capacity (V alt ) and its ratio to total respiration (V alt /V t) in potato slices aged for 24 h. With a monoclonal antibody against the alternative oxidase (AOX), Western blotting results showed that both H 2O 2 and SA treatments increased the AOX expression levels in aged potato tuber slices. However, the results of oxygen isotope discrimination experiments showed that H 2O 2 had no influence on the in vivo ARP activity (ρV alt ) and its contribution to V t(expressed as ρV alt /V t) in potato slices aged for 24 h, but SA had a significant influence on the ρV alt and ρV alt /V t values of the aged potato tuber slices. These results indicate that there are differences between the effects of H 2O 2 and SA on ARP in plant tissues. Both of them possess the ability to induce ARP capacity through inducing AOX expression. However, SA can simultaneously stimulate the operation of ARP, but H 2O 2 can not.

The Characteristic Relationship Between Oil Uptake and Moisture Content during the High Temperature Immersion Frying of Thin Potato Crisps

Thin potato crisps (2mm) were fried at 170℃, 180℃ and 190℃ for varioustimes from 10s to 180s inclusive. It was found that definite oil uptake, moisture loss trends existduring the frying process. No significant difference in the oil uptake or moisture loss ratesbetween flat-cut and ridge-cut crisps exists. Also found in this study was that an increased oiltemperature promoted higher moisture loss rates. In turn, the higher moisture loss rates contributedto a higher oil uptake rate. It was found, based on the volumetric plots of oil content υs. watercontent, that the oil uptake rate was proportional to the moisture loss rate. As a result, it hasbeen shown that there is a possibility of having a characteristic curve of oil uptake againstmoisture content.

Polyphenol Oxidase Activity and Inhibition in White Yam （Dioscorea Rotundata. Var. Laasirin） Chips as African Fries for Human Consumption

Polyphenol oxidase, a bi-functional enzyme, has been implicated in enzymatic browning of yam and other tubers in a negative way. The objective of this present study was to examine the activity of polyphenol oxidase in Dioscorea rotundata. Var. laasirin and the efficiency of heat and chemical treatments in inhibiting this enzyme. Crude Polyphenol Oxidase （PPO） of Dioscorea rotundata.Var. Laasirin was isolated and the kinetics studied using the lineweaver-burk plot. The activity of the enzyme was evaluated using spectrophotomeric method. Yam PPO catalyzes oxidation of various substrates with catechol being the most readily oxidized substrate. The Michaelis-Menten constant （Km） and maximum reaction velocity （Vmax） for yam PPO were 0.00037 and 0.3125 respectively. Inhibition data showed that the enzyme had least activity （71.70） when blanched at 95℃ for 7 mins with chemical treatment involving a combination of 0.5% Sodium metabisulphite （Food grade） and 0.5% Ascorbic acid （Food grade）. The activity was highest （83.02） when it was blanched at 95 ℃ for 7 rains. This study has shown that it is possible to inhibit polyphenol oxidase activity in white yam using the chemical pretreatments and processing conditions described in this study for possible adoption in the production of packaged frozen yam chips by food industries.

Effects of Cultivar, Frying Temperature and Slice Thickness on Oil Uptake and Sensory Quality of Potato Crisps Processed from Four Kenyan Potato Cultivars

The effects of potato cultivar, frying temperature and slice thickness on oil uptake and sensory quality of potato crisps were investigated in four Kenyan cultivars. Potato tubers were peeled, washed and cut into slices of thickness 1.0 mm, 1.5 mm and 2.0 mm. Each size was fried at a constant temperature of 170 ℃ for 3-5 minutes. For frying temperature evaluation, the potatoes for all cultivars were cut into a uniform thickness of 1.5 mm and fried at temperatures of 160, 170 and 180 ℃ for 2-5 minutes. Crisps made from the four cultivars differed significantly （P 〈 0.05） in oil absorbed which ranged from 35.12% in Dutch Robyjn to 36.52% in clone 391,691.96. Tuber dry matter differed significantly （P 〈 0.05） among the cultivars ranging from 20.99% in clone 391691.96 to 25.29% in variety Dutch Robyjn. Tuber dry matter content was found to be negatively correlated to oil content of crisps; oil content increased with decrease in dry matter content. For each cultivar, the oil content of crisps differed significantly （P 〈 0.05） with temperatures and was higher at frying temperatures of 160 ℃ and lowest at 180 ℃, respectively. The oil content was significantly （P 〈 0.05） higher in slices of 1.0 mm thick than in slices of 1.5 mm and 2.0 mm; the amount ofoil absorbed decreased with increase in slice thickness. There was significant correlation （P 〈 0.05, r = -0.834） between oil content as determined in the laboratory and sensory scores. Results showed that high dry matter, slice thickness and temperature of frying resulted in reduced oil absorption by crisps during processing.

Production and Quality Evaluation of Pringles from Composite Flour of Cocoyam and Wheat Flour

Work assessed ＂Pringles＂ as an imitate snack produced from composite flour of cocoyam and wheat. This was carried out in order to exploit the nutritional and aesthetic value of cocoyam （Colocasia escullenta Vat.） to improve the overall quality of the Pringles as against its production from potato and wheat composite flour. Composite flour （100%：0%, 90%：10%, 80%：20%, 70%：30%, 60%：40% and 50%：50%） of cocoyam and wheat respectively as the major raw materials were adopted and used for the production of the Pringles. Physicochemical analysis （pH, water absorption capacity （WAC）, bulk density （BD） and swelling capacity （SC））; proximate analysis （protein, fats, ash, moisture and carbohydrate content） and sensory evaluation （colour, texture, taste and overall acceptability） were carried out on the samples produced using standard methods. Physicochemical analysis showed the pH of 5.48 to 6.61, WAC （12.00 to 17.50）, BD （1.43 to 1.56） and SW （1.03 to 1.38）. However, sample with 10% cocoyam and 90% wheat composite flour gave the best physicochemical properties of pH （5.98）, WAC （14.00）, BD （1.56） and SC （1.38）. The proximate analysis showed that carbohydrate content ranging between 53.36 to 61.12, and protein content （8.17 to 12.29）, fat content （16.67 to 23.97）, ash content （3.49 to 45.53）, fiber content （1.71 to 2.83） and moisture content （8.76 to 14.54）. Sample B equally gave the nutrient proximate combination of appreciable percentage on the average. The result of the sensory evaluation showed that there is no significant difference between the samples produced in terms of aroma. There is a significant different between samples A, B and the remaining samples in terms of colour and taste. On the overall acceptability, samples A, C and D showed no significant difference but the highest mean score was found with sample B. Conclusively, acceptable snack （Pringles） can be produced from cocoyam and wheat in ratio 90%： 10%, respectively.

The Inhibitory Role of Plant Extracts on Acrylamide Formation in Potato Chips

This paper investigated the efficiency of antioxidant of Thyme and extract of cumin on the reduction of acrylamide in potato chips and summarized the optimal levels of two additives. Seven experimental groups including a control group were organized for both of additives.

Sensory and Organoleptic Characteristic, Zinc and Iron Content of Fortified Chips from Cassava Flour

Iron fortification can cause several biophysicochemical modifications. Those depend on many factors, such as iron fortificant and the food carrier. There were four groups of chips： 1） non-fortified wheat flour chips （K1）; 2） non-fortified cassava flour chips （K2）; 3） fortified cassava flour chips, each with ZnSO4 30 ppm and NaFe EDTA （K3） 30 ppm and 4） fortified cassava flour chips, each with ZnSO4 50 ppm and NaFe EDTA （K4） 50 ppm. The chips were evaluated for sensory characteristic （color, taste, flavor, and texture）, organoleptic characteristics tested by preference test, as well as zinc and iron contents. Zinc and iron contents were analyzed by Atomic Absorption Spectophotometric method. The results showed that both fortificants did not affect the sensory characteristic of cassava flour chips. The preference test showed that color, taste, and flavor of Kl chips as a control, were mostly liked, but there was no significant difference preference of texture. Moreover, preference test using K2 as control showed that color of K3 was mostly liked, but there was no significant difference preference of taste, flavor and texture. Fortification can increase the contents of zinc and iron in cassava flour chips. The panelist can accept the fortified cassava chips as well as wheat flour chip, as a consequence, both can be a potential way to combat the iron deficiency anemia.

Cyanide Contents of Leaves of Commonly Consumed Cassava Varieties from Three Geographical Regions of Ghana

Consuming a cyanogenic plant is an etiological factor to the persistence of iodine deficiency in the post salt iodization phase. Ghana, notably the Northern belt, still reports of iodine deficiency after 14 years of mandatory consumption of iodized salt by an Act of Parliament. The study aimed at determining the cyanide contents of leaves of commonly consumed cassava varieties in Ghana and investigating the effects of some environmental factors on cyanide content. Three communities each from Southern, Middle and Northern Ghana served as the study sites from where young, non-diseased and fully-spread cassava leaves were sampled from plants of commonly consumed cassava varieties. Cyanide was analyzed by the standard color^metric method based on the chloramine-T/pyridine-barbituric acid protocol （4500-CN E）. Cassava leaves from Northern Ghana had significantly higher mean cyanide content （177.22 ± 20.82 ppm） than those from Middle （130.83± 33.00 ppm） and Southern Ghana （127.24 ± 37.54 ppm） （P 〈 0.001）. Two-factor ANOVA showed significantly higher adverse environmental effects on cyanide contents of leaves of unimproved cassava varieties than improved ones （R2 = 0.627, P = 0.023）. From multiple regression analysis, temperature was the most significant environmental factor explaining 33% of the variability in cyanide content （R2 = 0.331, P = 0.002）, followed by altitude （R2 = 0.106, P = 0.049） and rainfall （R2 = 0.084, P = 0.062）. The high cyanide contents of cassava leaves from Northern Ghana, due principally to the high atmospheric temperature, may be a contributory factor to the high prevalence of goiter and the persistence of iodine deficiency in that geographic region.

Diversification of Cassava Flour in the Manufacture of Gluten-Free Flakes Enriched with Dietary Fibers from Virgin Coconut Oil Waste Flour

Food diversification is a way to strengthen national food security, for example by reducing the dependence on wheat flour as a main raw material of various food products through the use of cassava flour. Cassava flour, a rich source of carbohydrates, can be used in the making of flakes. In this study, the Virgin coconut oil （VCO） waste flour was added in cassava flour to produce gluten-free cassava flour flakes with high dietary fiber contents. The six different formulas of flakes were used in this study with addition of 0% （control）, 10%, 20%, 30%, 40% and 50% coconut waste flour, respectively. Then, the chemical and microbiological characteristics of the flakes were measured. Based on the proximate data, both flours have a good quality. The microbiological analysis shows cassava flour and coconut waste flour have good sanitation and food safety. Results showed that flakes with 80% cassava flour and 20% coconut waste flour are gluten-free and contain 2.52% water, 2.27% ash, 14.40% fat, 4.50% protein, 76.31% carbohydrate, 8.56% dietary fiber. Therefore, it can be said that cassava flour flakes can serve as gluten-free and rich dietary fiber ready-to-eat food.